APA (7th ed.) Citation

Aston, G., & Tiffney, J. (1977). A guide to improving food hygiene. Northwood Publications Ltd.

Chicago Style (17th ed.) Citation

Aston, Graham, and John Tiffney. A Guide to Improving Food Hygiene. London: Northwood Publications Ltd, 1977.

MLA (9th ed.) Citation

Aston, Graham, and John Tiffney. A Guide to Improving Food Hygiene. Northwood Publications Ltd, 1977.