O[tto]. K. Werckmeister in Paul Klee: Das Frühwerk 1883–1922. Ed. Armin Zweite. Exh. cat., Stadtische Galerie und Lenbach Galerie, Munich. Munich, 1979, p. 185, remarks that the title of this work was changed from "Abstractes [sic] Aquarell" to "Schweres Pathos" when the Neue Münchener Secession travelled to Frankfurt in 1917; notes that it was sold in Frankfurt.
O[tto]. K[arl]. Werckmeister. Versuche über Paul Klee. Frankfurt, 1981, p. 36.
Sabine Rewald. Paul Klee: The Berggruen Klee Collection in The Metropolitan Museum of Art. Exh. cat., The Metropolitan Museum of Art. New York, 1988, pp. 76–77, 273, 317, ill. (color and bw).
O[tto]. K. Werckmeister. The Making of Paul Klee's Career, 1914–1920. Chicago, 1989, pp. 75–76, 273 nn. 52–54, calls it "Grave Pathos"; comments that since three works sold after their titles were changed, including this one, "by late 1916 Klee would have been able to discern that his hermetic abstraction of 1915 could be made palatable to the public if he imbued it, by means of new titles, with a suggestive literary significance"; notes that since the new title is written in pencil in Klee's oeuvre catalogue, it is not possible to determine exactly when the title was changed.
Phyllis Williams Lehmann. "A Roman Source for Klee's 'Athlete's Head'." Art Bulletin 72 (December 1990), p. 646 n. 39.
Roland Dorn in Stiftung und Sammlung Sally Falk. Ed. Roland Dorn, Karoline Hille, and Jochen Kronjäger. Mannheim, 1994, pp. 164, 195–96, no. 127, calls it "No: 175"; notes that Falk purchased this work from Exh. Frankfurt 1917 and deposited it at the Kunsthalle Mannheim in May 1918; states that it was sold by Pfrunder to Neumann in October 1919, tentatively identifying it on a list of works sent to Neumann as no. 27 "Farbenphantasie".
Jenny Anger. "Modernism and the Gendering of Paul Klee." PhD diss., Brown University, 1997, vol. 1, pp. 74–75, 82; vol. 2, fig. 50 (color).
Josef Helfenstein and Christian Rümelin, ed. Paul Klee: Catalogue Raisonné. Ed. Paul Klee Foundation, Museum of Fine Arts, Berne. Vol. 2, 1913–1918. New York, 2000, p. 299, no. 1509, ill., as "Schweres Pathos (Heavy Pathos)".
Jenny Anger. Paul Klee and the Decorative in Modern Art. Cambridge, England, 2004, pp. 83–84, 214, 265 nn. 185, 186, fig. 29, calls it "Heavy Pathos".