Não informado. (1958). Information circular. Mines Branch, Department of Energy, Mines and Resources.
Παραπομπή σε μορφή Chicago (17η εκδ.)Não informado. Information Circular. Ottawa: Mines Branch, Department of Energy, Mines and Resources, 1958.
Παραπομπή σε μορφή MLA (8th εκδ.)Não informado. Information Circular. Mines Branch, Department of Energy, Mines and Resources, 1958.
Πρόσοχή: Οι παραπομπές μπορεί να μην είναι 100% ακριβείς.