Cite

The castle number nine / story and pictures by Ludwig Bemelmans.

MLA

Bemelmans, Ludwig, 1898-1962. The castle number nine / story and pictures by Ludwig Bemelmans.. c1937.. https://collections.library.yale.edu/catalog/15510537.

APA, 6th edition

Bemelmans, Ludwig, 1898-1962. (c1937.)[The castle number nine / story and pictures by Ludwig Bemelmans.]. https://collections.library.yale.edu/catalog/15510537.