2014. 'The Problem of the Portrait Copies painted by Rubens in Madrid, 1628-29'. In: European Paintings 15th-18th Century. Copying, Replicating and Emulating. CATS Proceedings I, 2012 Archetype Publications in association with CATS (Centre for Art Technological Studies and Conservation), London. 87-94
2011. Rubens. Copies and Adaptations from Renaissance and Later Artists. Italian Artists, III. Artists working in Central Italy and France, 2 vols (Corpus Rubenianum Ludwig Burchard, Part XXVI, 2) Harvey Miller Publishers, London and Turnhout.
2010. Rubens. Copies and Adaptations from Renaissance and Later Artists. Italian Artists, II. Titian and North Italian Artists, 2 vols (Corpus Rubenianum Ludwig Burchard, Part XXVI, 2) Harvey Miller Publishers, London and Turnhout.
2010. Rubens. Copies and Adaptations from Renaissance and Later Artists. Italian Artists, I. Raphael and his School, 2 vols (Corpus Rubenianum Ludwig Burchard, Part XXVI, 2) Harvey Miller Publishers, London and Turnhout.
2010. 'Caravaggio and the British'. In: CLAUDIO STRINATI and AESSANDRO ZUCCARI, eds., I Caravaggeschi. Nell'anno di Caravaggio. Il primo repertorio completo dedicato al pittori caravaggeschi in Europa Skira Editore, Milan. 275-283
2010. 'Connoisseurship of the Arts'. In: Nicholas Lanier, 1588-1666. A Portrait Revealed The Weiss Gallery, London. 39-49
2009. 'The Man who would be British' Tate Etc. 15, 48-51
2009. 'Rubens' italienische Kopien. Ein chronologischer Abriss'. In: Rubens im Wettstreit mit Alten Meistern. Vorbild und Neuerfindung (Bayerischen Staatsgemäldesammlungen, Alte Pinakothek, Munich, 2009-10) Hatje Cantz Verlag, Ostfildern. 56-81
2009. No. 1, 'Isabella d'Este, Markgräfin von Mantua, in Rot' (134-139); No. 2, 'Kaiser Karl V' (140-149); No. 4, 'Amor schnitz den Bogen' (156-163); No. 9, 'Prinz Philipp von Spanien im Prunkharnisch' (186-195); No. 10, 'Dame in Weiß' (196-201); No. 11, 'Mädchen mit Fächer' (202-207); No. 12, Titian, 'Adam und Eva' (208-213); No. 13, 'Adam und Eva' (214-219); No. 14, 'Raub der Europa' (220-227); No. 15, 'Mädchen im Pelz' (228-235). In: Rubens im Wettstreit mit Alten Meistern. Vorbild und Neuerfindung (Bayerischen Staatsgemäldesammlungen, Alte Pinakothek, Munich, 2009-10) Hatje Cantz Verlag, Ostfildern.
2006. 'Rubens and Raphael: The Designs for the Tapestries in the Sistine Chapel'. In: KATLIJNE VAN DER STIGHELEN, ed., Munuscula amicorum. Contributions on Rubens and his Colleagues in honour of Hans Vlieghe Brepols, Turnhout. 259-282
2005. Introduction. In: Lives of Rubens by Giovanni Baglione, Joachim von Sandrart, Roger de Piles London: Pallas Athene. 7-22
2003. 'Nicholas Lanier (1588-1666) and the Origins of Drawings Collecting in Stuart England'. In: CHRISTOPHER BAKER, CAROLINE ELAM and GENEVIEVE WARWICK, eds., Collecting Prints and Drawings in Europe, c.1500-1750 Ashgate in association with The Burlington Magazine. 85-121
2002. Rubens. Drawing on Italy National Gallery of Scotland, Edinburgh.
2001. 'Van Dyck: A Catholic Artist in Protestant England, and the Notes on Painting Compiled by Francis Russell, 4th Earl of Bedford'. In: HANS VLIEGHE, ed., Anthony van Dyck (1599-1641): Conjectures and Refutations Brepols Publishers, Turnhout. 167-198
2001. 'Orazio Gentileschi at the Court of Charles I'. In: KEITH CHRISTIANSEN and JUDITH W. MANN, eds., Orazio and Artemisia Gentileschi The Metropolitan Museum of Art, New York, and Yale University Press, New Haven and London. 223-231
2001. 'Orazio Gentileschi alla corte di Carlo I'. In: KEITH CHRISTIANSEN and JUDITH W. MANN, eds., Orazio e Artemisia Gentileschi Palazzo Venezia, Rome, and Skira, Milan. 223-231
2000. 'Rubens as Thief'. In: HANS VLIEGHE, ARNOUT BALIS and CARL VAN DE VELDE, eds., Concept, Design and Execution in Flemish Painting (1550-1700) Brepols Publishers, Turnhout. 153-170
2000. 'Taste and Connoisseurship at the Court of Charles I: Inigo Jones and the Work of Giulio Romano'. In: EVELINE CRUICKSHANKS, ed., The Stuart Courts Sutton Publishing, Stroud. 118-140
2000. 'Orazio Gentileschi and some Netherlandish artists in London: the patronage of the Duke of Buckingham, Charles I, and Henrietta Maria' Simiolus: Netherlands Quarterly for the History of Art. XXVIII(3), 103-128
1999. 'Raphael Copies and Exemplary Picture Galleries in Mid-Eighteenth Century London' Zeitschrift für Kunstgeschichte. LXII, 394-417
1998. 'Peter Oliver at the Court of Charles I: New Drawings and Documents' Master Drawings. XXXVI(2), 123-153
1996. 'Padre Resta as a Collector of Carracci Drawings' Master Drawings. XXXIV(1), 3-71
1995. '"Damaged by Time and Rubens": Rubens's Restorations and Retouchings' Apollo. CXLII(406 New Series), 16-23
1994. 'Van Dyck and the Earl of Northumberland: Taste and Collecting in Stuart England'. In: SUSAN J. BARNES and ARTHUR K. WHEELOCK, JR, eds., Van Dyck: 350, Studies in the History of Art 46, Symposium Papers XXVI National Gallery of Art, Washington. 281-324
1994. 'Rubens's Collection of Drawings: His Attributions and Inscriptions' Wallraf-Richartz-Jahrbuch: Studien zür niederländischen Kunst: Festschrift für Prof. Dr. Justus Müller Hofstede,. LV, 333-351
1993. 'The Architectural Patronage of Algernon Percy, 10th Earl of Northumberland'. In: JOHN BOLD and EDWARD CHANEY, eds., English Architecture, Public and Private: Essays for Kerry Downes The Hambledon Press, London and Rio Grande. 55-80
1992. 'Van Dyck's Pictures for the Duke of Buckingham: The Elephant in the Carpet and the Dead Tree with Ivy' Apollo. CXXXVI(365 New Series), 37-47
1992. 'Inigo Jones, Italian Art, and the Practice of Drawing' Art Bulletin. LXXIV, 247-270
1992. Entries for Catalogue No. 32, Rubens, Leda and the Swan after Michelangelo (pp. 114-116); No. 40, Rubens, The Emperor Charles V after Titian (pp. 140-142); No. 48, Rubens, Portrait of a Young Lady after Titian (pp. 164-166); No. 49, Rubens, Woman with a Fan after Titian (pp. 168-170). In: Rubens and the Italian Renaissance Australian National Gallery, Canberra.
1990. 'Padre Resta's Flemish Drawings: Van Diepenbeeck, Van Thulden, Rubens, and the School of Fontainebleau' Master Drawings. XXVIII, 3-53
1990. 'Van Dyck's "Cabinet de Titien": The Contents and Dispersal of his Collection' The Burlington Magazine. CXXXII, 680-695
1989. 'Rubens or van Dyck? "Mucius Scaevola before Lars Porsenna" and some Problematic Drawings' Mercury. 10, 26-40
1988. 'Cannibalized Prints and Early Art History: Vasari, Bellori and Fréart de Chambray on Raphael' Journal of the Warburg and Courtauld Institutes. LI, 210-220
1988. 'Some Early Collectors of Rubens Drawings in England'. In: CATHERINE WHISTLER and JEREMY WOOD, eds., Rubens in Oxford: An Exhibition of Drawings from Christ Church and the Ashmolean Museum The Picture Gallery, Christ Church, Oxford, and P. & D. Colnaghi & Co., London. 8-18