APA (7th ed.) Citation

Young, E., Young, B., & James, C. (1991). Help your child with science. Cambridge University Press.

Chicago Style (17th ed.) Citation

Young, Ella, Beverley Young, and Chris James. Help Your Child with Science. Cambridge: Cambridge University Press, 1991.

MLA (9th ed.) Citation

Young, Ella, et al. Help Your Child with Science. Cambridge University Press, 1991.