The theme of "Klein" draws upon a wide range of literary and cultural references, including characters, academics, and symbolic figures. Authors such as Louis Tracy portray a Klein facing poverty and artistic challenges, while H. De Vere Stacpoole presents him as an ethically complex character in a gothic mystery.
In contrast, Thomas Dibdin honors Klein as a talented artist, and Montague Glass employs the name in a humorous business setting. The term also applies to historical individuals such as the mathematician Felix Klein, mentioned in Popular Science Monthly. These differing depictions highlight "Klein" as a name of considerable depth, connecting realism, fiction, and intellectual heritage across various genres and time periods.