Cita APA (7a ed.)

Ludwig, H. (1894). The Holothurioidea. Museum of Comparative Zoölogy.

Cita Chicago Style (17a ed.)

Ludwig, Hubert. The Holothurioidea. Cambridge: Museum of Comparative Zoölogy, 1894.

Cita MLA (9a ed.)

Ludwig, Hubert. The Holothurioidea. Museum of Comparative Zoölogy, 1894.