APA-referens (7:e uppl.)

Ohuma, E., Papageorghiou, A., Villar, J., & Altman, D. (2013). Estimation of gestational age in early pregnancy from crown-rump length when gestational age range is truncated: The case study of the INTERGROWTH-21st Project. BioMed Central.

Chicago-referens (17:e uppl.)

Ohuma, E., A. Papageorghiou, J. Villar, och D. Altman. Estimation of Gestational Age in Early Pregnancy from Crown-rump Length When Gestational Age Range Is Truncated: The Case Study of the INTERGROWTH-21st Project. BioMed Central, 2013.

MLA-referens (9:e uppl.)

Ohuma, E., et al. Estimation of Gestational Age in Early Pregnancy from Crown-rump Length When Gestational Age Range Is Truncated: The Case Study of the INTERGROWTH-21st Project. BioMed Central, 2013.