APA (7th ed.) Citation

Howells, W. W. (1947). Mankind so far. Sigma Books.

Chicago Style (17th ed.) Citation

Howells, W. W. Mankind so Far. London: Sigma Books, 1947.

MLA (8th ed.) Citation

Howells, W. W. Mankind so Far. Sigma Books, 1947.

Warning: These citations may not always be 100% accurate.