APA (7th ed.) Citation

Helwich, O., & Baring, J. L. (1936). Practical infra-red photography. Fountain Press.

Chicago Style (17th ed.) Citation

Helwich, Othmar, and J. L. Baring. Practical Infra-red Photography. London: Fountain Press, 1936.

MLA (8th ed.) Citation

Helwich, Othmar, and J. L. Baring. Practical Infra-red Photography. Fountain Press, 1936.