1Franz Koenigs Haarlem • by 1930 until [d.] 1941 Vincent van Gogh en zijn tijdgenooten, (exh. cat.) Stedelijk Museum Amsterdam 1930, no. 306. The painting was on loan to the Boijmans Museum, Rotterdam, from 17 January 1933 to 24 September 1940, Information kindly provided by Christine F. Koenigs, Amsterdam, in an E-Mail correspondence with Foundation E.G. Bührle Foundation, Zurich, 26 September–2 October 2014.
2The estate of Franz Koenigs Haarlem • 1941–1947 The estate of Franz Koenigs was settled only in 1947, after Koenig's wife, Anna Koenigs-von Kalckreuth, had died in November 1946, E-Mail correspondence as above, n. (1).
3Kornelie van Eyck-Koenigs London • 1947/48 Daughter of Franz and Anna Koenigs, Les deux amies was quoted as «Twee frowen» in the list of her share, E-Mail correspondence as above, n. (1).
4Georges Wildenstein New York & Paris • by 1948–1954 Six Masters of Post-Impressionism, Cézanne, Gauguin, Lautrec, Rousseau, Seurat, Van Gogh, Wildenstein Galleries, New York 1948, no. 33; AStEGB, Letter from Daniel Wildenstein, New York, 17 April 1954, to Emil Bührle, offering eight artworks, including Lautrec, Les deux amies.
5Emil Bührle Zurich • 10 June 1954 until [d.] 28 November 1956 Acquired from the above for $ 65.000, AStEGB, Invoice from Anstalt für Kunsthandel, Vaduz [Wildenstein], 24 May 1954, for four works of art, including Toulouse-Lautrec, Les deux amies, amounting to a total of $ 172.500, and Letter from Anstalt für Kunsthandel, Vaduz, to Emil Bührle, 10 June 1954, acknowledging receipt of this amount.
5Given by the heirs of Emil Bührle to the Foundation E.G. Bührle Collection Zurich • 1960 Inv. 106.
AStEGB = Archive of the Foundation E.G. Bührle Collection, Zurich
Madeleine Grillaert Dortu, Toulouse-Lautrec et son œuvre, Catalogue des peintures, aquarelles, monotypes…, 4 vol., New York, 1971.
1903Siebente Kunstausstellung der Berliner Secession Ausstellungshaus der Berliner Secession (Kantstrasse) • Berlin • 1903 no. 115 or 123.
1925Impressionisten, Herbstausstellung Galerie Paul Cassirer • Berlin • 1925 no. 58 (?).
1930Vincent van Gogh en zijn tijdgenooten Stedelijk Museum Amsterdam • 1930 no. 306.
1948Six Masters of Post-Impressionism, Cézanne, Gauguin, Lautrec, Rousseau, Seurat, Van Gogh Wildenstein Galleries• New York• 1948 no. 33.
1958Sammlung Emil G. Bührle, Festschrift zu Ehren von Emil G. Bührle zur Eröffnung des Kunsthaus-Neubaus und Katalog der Sammlung Emil G. Bührle Kunsthaus Zurich • 1958 no. 205.
1959De Géricault à Matisse, Chefs-d'œuvre français des collections suisses Petit Palais • Paris • 1959 no. 130.
1990The Passionate Eye, Impressionist and Other Master Paintings from the Collection of Emil G. Bührle, Zurich, Catalogue of the Exhibition in Commemoration of the 100th Birthday of the Collector Emil G. Bührle National Gallery of Art, Washington, D.C. • Musée des beaux-arts de Montréal • Yokohama Museum of Art • Royal Academy of Arts, London • 1990–91 no. 67.
2005Bordell und Boudoir, Schauplätze der Moderne, Cézanne, Degas, Toulouse-Lautrec, Picasso Kunsthalle Tübingen • 2005 no. 73.
2010Van Gogh, Cézanne, Monet, Die Sammlung Bührle zu Gast im Kunsthaus Zürich Kunsthaus Zurich • 2010 no. 106.
2017Chefs-d'oeuvre de la collection Bührle, Manet, Cézanne, Monet, Van Gogh… Fondation de l'Hermitage • Lausanne • 2017 no. 37.
1954«La vocation du collectionneur» in Arts (471, July) • 1954 (ill.).
1956François Daulte «Le chef-d'œuvre d'une vie: la collection Buhrle» in Connaissance des Arts (52) • 15 June 1956 • p. 35 (ill.).
1963René Wehrli «Emil G. Bührle, Zurich, French Nineteenth-Century Paintings» in Great Private Collections Douglas Cooper (ed.) • New York • 1963 • p. 221.
1964Philippe Huisman • Marcel G. Dortu Lautrec par Lautrec Lausanne & Paris • 1964 • pp. 129 (ill.), 131.
1969Giorgio Caproni • Gabriele Mandel Sugana L'opera completa di Toulouse-Lautrec Milan • 1969 • no. 410 (ill.; 21977; German edition: Das Gesamtwerk von Toulouse-Lautrec, Lucerne etc. 1969 • Spanish edition: La obra pictórica completa de Toulouse-Lautrec, Barcelona 1970; 21988 • English edition: Gabriele Mandel Sugana, Denys Sutton, The Complete Paintings of Toulouse-Lautrec, London 1973 • French edition: Bruno Foucart, Gabriele Mandel Sugana, Tout l'œuvre peint de Toulouse-Lautrec, Paris 1986, no. 530 [ill.]).
1969André Fermigier Toulouse-Lautrec Paris • 1969 • p. 172, fig. 144.
1971Marcel G. Dortu Toulouse-Lautrec et son œuvre, Catalogue des peintures, aquarelles, monotypes, reliure, vitrail, céramique, dessins New York • 1971 • vol. 3 • no. P.602 (ill.; German edition: Marcel G. Dortu, J. A. Méric, Toulouse-Lautrec, Das Gesamtwerk, Frankfurt/M. etc. 1980).
1973Leopold Reidemeister etc. Stiftung Sammlung Emil G. Bührle • Fondation Collection Emil G. Bührle • Foundation Emil G. Bührle Collection Zurich & Munich • 1973 • no. 97 (ill.; 21986).
1980Sophie Monneret L'Impressionnisme et son époque, Dictionnaire international illustré vol. 3 • Paris • 1980 • p. 140, entry for Toulouse-Lautrec.
1994Emil Maurer Stiftung Sammlung E.G. Bührle, Zürich Bern • 1994 • p. 30 (ill.; English edition: Foundation E.G. Bührle Collection, Zurich, Bern 1995).
2004Lukas Gloor, Marco Goldin (ed.) Foundation E.G. Bührle Collection, Zurich, Catalogue vol. 3 • Conegliano & Zurich • 2004 • no. 155 (ill.; German edition: Stiftung Sammlung E.G. Bührle, Katalog • Italian edition: Fondazione Collezione E.G. Bührle, Catalogo).
2017Il mondo fuggevole di Toulouse-Lautrec (exh. cat.) • Palazzo Reale • Milan • 2017–2018 • p. 328 (ill.).
2021Lukas Gloor «The Holdings of the Emil Bührle Collection: Illustrated List of All 633 Purchases» in The Emil Bührle Collection: History, Full Catalogue and 70 Masterpieces Swiss Institute for Art Research, Zurich (ed.) • Munich • 2021 • no. 388 (ill.).