Não informado. (1962). Phosphorus and potassium. British Sulphur Corporation.
Chicago (17e ed.) BronvermeldingNão informado. Phosphorus and Potassium. London: British Sulphur Corporation, 1962.
MLA (8e ed.) BronvermeldingNão informado. Phosphorus and Potassium. British Sulphur Corporation, 1962.
Let op: Deze citaties zijn niet altijd 100% accuraat.