Madeline and the bad hat / written and illustrated by Ludwig Bemelmans.
MLA
Bemelmans, Ludwig, 1898-1962. Madeline and the bad hat / written and illustrated by Ludwig Bemelmans.. December, 1956.. https://collections.library.yale.edu/catalog/15510536.
APA, 6th edition
Bemelmans, Ludwig, 1898-1962. (December, 1956.)[Madeline and the bad hat / written and illustrated by Ludwig Bemelmans.]. https://collections.library.yale.edu/catalog/15510536.