Cita APA (7th ed.)

McLaren, D. S., & Frigg, M. (1997). Sight and life manual on vitamin A deficiency disorders (VADD). Task Force Sight and Life.

Cita Chicago (17th ed.)

McLaren, Donald S., i Martin Frigg. Sight and Life Manual on Vitamin A Deficiency Disorders (VADD). Switzerland: Task Force Sight and Life, 1997.

Cita MLA (9th ed.)

McLaren, Donald S., i Martin Frigg. Sight and Life Manual on Vitamin A Deficiency Disorders (VADD). Task Force Sight and Life, 1997.