APA (7th ed.) Citation

Sitter, W. d., & Schaar, J. P. v. d. (1934). Kosmos. Amsterdam Academic Archive.

Chicago Style (17th ed.) Citation

Sitter, William de, and Jan Pieter van der Schaar. Kosmos. [Amsterdam]: Amsterdam Academic Archive, 1934.

MLA (9th ed.) Citation

Sitter, William de, and Jan Pieter van der Schaar. Kosmos. Amsterdam Academic Archive, 1934.