APA (7e ed.) Bronvermelding

Elderton, W. P., & Johnson, N. L. (1969). Systems of frequency curves. Cambridge University.

Chicago (17e ed.) Bronvermelding

Elderton, William Palin, en Norman Lloyd Johnson. Systems of Frequency Curves. Cambridge: Cambridge University, 1969.

MLA (9e ed.) Bronvermelding

Elderton, William Palin, en Norman Lloyd Johnson. Systems of Frequency Curves. Cambridge University, 1969.