Most of these were published by Insel Verlag, a German publisher in Leipzig. The format of small books by worthy authors and poets was copied by Penguin when they created their King Penguin editions. These in turn were part of the inspiration for the Modern Library.
Bertold Brecht. Liebesdichte. Insel-Bucherie Nr. 852.
Rainer Maria Rilke. Das Stunden-Buch. Insel Taschenbuch 2.
Rainer Maria Rilke. Duineser Elegian. Suhrkamp Verlag.
Walter Benjamin. Goethes Wahlverwandtschaften. Insel-Bucherie Nr. 812.