Gaya APA

Kohl, H, R. (1975). The open classroom : a practical guide to a new way of teaching / Herbert R. Kohl . London: Methuen n Co.

Gaya MLA

Kohl, Herbert, R.. "The open classroom : a practical guide to a new way of teaching / Herbert R. Kohl". London: Methuen n Co, 1975. Skripsi.