Não informado. (1973). Current contents. Institute for Scientific Information.
Chicago (17e ed.) BronvermeldingNão informado. Current Contents. Philadelphia, Pa: Institute for Scientific Information, 1973.
MLA (8e ed.) BronvermeldingNão informado. Current Contents. Institute for Scientific Information, 1973.
Let op: Deze citaties zijn niet altijd 100% accuraat.