Gaya APA

Bonvillian, J. et al (2020). E-book Simplified Signs : A Manual Sign-Communication System for Special Populations, Volume 2. . : Open Book Publishers.

Gaya MLA

Bonvillian, John. et al. "E-book Simplified Signs : A Manual Sign-Communication System for Special Populations, Volume 2.". : Open Book Publishers, 2020. Text.