Não informado. (1938). The American Biology Teacher. National Association of Biology Teachers.
Παραπομπή σε μορφή Chicago (17η εκδ.)Não informado. The American Biology Teacher. Reston, Va: National Association of Biology Teachers, 1938.
Παραπομπή σε μορφή MLA (8th εκδ.)Não informado. The American Biology Teacher. National Association of Biology Teachers, 1938.
Πρόσοχή: Οι παραπομπές μπορεί να μην είναι 100% ακριβείς.