Não informado. (1931). Metallurgical Abstracts. Institute of Metals.
Chicago (17e ed.) BronvermeldingNão informado. Metallurgical Abstracts. London: Institute of Metals, 1931.
MLA (8e ed.) BronvermeldingNão informado. Metallurgical Abstracts. Institute of Metals, 1931.
Let op: Deze citaties zijn niet altijd 100% accuraat.