Most of these are out of print or difficult to get hold of. Some of them are conservation/art history journals that may be available from the archives of the relevant professional body. The Tate 2006 catalogue can be purchased from Amazon and others through the online bookstore Abe Books. In exceptional circumstances SC may be able to copy or scan unavailable texts for a fee to cover time/processing/postage.
'An Experimental Painting by John Constable', The Conservator, Vol 12, 1988, pp.52-56, United Kingdom Institute for Conservation (UKIC)
'The Constable Project: current research into materials and techniques', Pre-prints to Conservation Today 30th Anniversary Conference 1988, pp.59-63, UKIC
'Constable's Oil Painting Materials and Techniques' in Constable, exhibition catalogue, Tate Gallery, London, 1991, pp.493-529
'Constable's Oil Sketches on Paper and Millboard'. Pre-prints to Institute of Paper Conservation Conference Manchester 1992, pp.123-128
'Mixing and mingling: John Constable's Oil Paint mediums (1802-1837), including the analysis of the Manton Paint box (1837)', Painting Techniques: History, Materials and Studio Practice, IIC Congress Papers 1998, pp.211-216
'“Very Great Difficulty in Composition and Execution": The materials and techniques of Constable's cloud and sky studies of the 1820s', Constable's Skies, Salander-O'Reilly Galleries, New York, 2004, pp.123-152
'The Painting Techniques of Constable's "Six-Footers"', pp.50-67 and catalogue entry for Constable's palette and paintbox pp.194-197, Constable, The Great Landscapes, exhibition catalogue, Tate, London, 2006
'Fit for Purpose: Constable's Use of Millboard and Paper for Oil Sketching, c.1809-29', Constable's Oil sketches 1809-29: The Maria Bicknell Years, Salander-O'Reilly Galleries, New York, 2007, pp.115-141
'The Materials and Techniques of The Lock, 1825, by John Constable', in Constable: The Lock, Sotheby's, London 9 December 2015, individual sale catalogue, pp.46-53
John Constable RA 1776-1837: Dedham Vale with the River Stour in Flood from the Grounds of Old Hall, East Bergholt, (with Anne Lyles), privately published by Andrew Clayton Payne Ltd., London, 2015, pp.22-26
John Constable, R.A. Hampstead Heath with Branch Hill Pond, (with Anne Lyles), privately published by Andrew Clayton Payne Ltd., London, 2015, pp.13-26
'Fit for Purpose: 30 Years of the Constable Research Project', Studying the European Visual Arts 1800-1850: Paintings, Sculpture, Interiors and Art on Paper, CATS Proceedings III, 2016, pp.94-108. Archetype Publications (London).
Free download available here
'A ‘Jackson Pollock’ of the 1830s: The painting materials and techniques of A red-tiled Cottage with Rainbow and Windmill, c.1833-37, John Constable R.A.', Sotheby's Old Master Evening Sale Catalogue, 5th July 2017, Lot 60 http://www.sothebys.com/content/dam/sothebys/PDFs/Constable_Essay.pdf