Não informado. (1936). Frontiers: A magazine of natural history. Academy of Natural Sciences of Philadelphia.
Παραπομπή σε μορφή Chicago (17η εκδ.)Não informado. Frontiers: A Magazine of Natural History. Philadelphia, Pa: Academy of Natural Sciences of Philadelphia, 1936.
Παραπομπή σε μορφή MLA (8th εκδ.)Não informado. Frontiers: A Magazine of Natural History. Academy of Natural Sciences of Philadelphia, 1936.
Πρόσοχή: Οι παραπομπές μπορεί να μην είναι 100% ακριβείς.