APA

Keith A., Robertson J. & Blackie. (1958). The principles of arithmetic. London: Blackie & Son Limited.

Chicago

Keith Alexander, Robertson James and Blackie. 1958. The principles of arithmetic. London: Blackie & Son Limited.

Harvard

Keith A., Robertson J. and Blackie. (1958). The principles of arithmetic. London: Blackie & Son Limited.

MLA

Keith Alexander, Robertson James and Blackie. The principles of arithmetic. London: Blackie & Son Limited. 1958.