APA (7th ed.) Citation

Bishop, D., & Bishop, S. (1998). "Twin language": A risk factor for language impairment?

Chicago Style (17th ed.) Citation

Bishop, D., and S. Bishop. "Twin Language": A Risk Factor for Language Impairment? 1998.

MLA (9th ed.) Citation

Bishop, D., and S. Bishop. "Twin Language": A Risk Factor for Language Impairment? 1998.

Warning: These citations may not always be 100% accurate.