Ultrasound is not unsound, but safety is an issue.

MLA

Salvesen, K. A., and C. Lees. “Ultrasound Is Not Unsound, but Safety Is an Issue.” Ultrasound in Obstetrics & Gynecology : The Official Journal of the International Society of Ultrasound in Obstetrics and Gynecology, vol. 33, no. 5, May 2009, pp. 502–05. EBSCOhost, https://doi.org/10.1002/uog.6381.

APA

Salvesen, K. A., & Lees, C. (2009). Ultrasound is not unsound, but safety is an issue. Ultrasound in Obstetrics & Gynecology : The Official Journal of the International Society of Ultrasound in Obstetrics and Gynecology, 33(5), 502–505. https://doi.org/10.1002/uog.6381

Chicago

Salvesen, K A, and C Lees. 2009. “Ultrasound Is Not Unsound, but Safety Is an Issue.” Ultrasound in Obstetrics & Gynecology : The Official Journal of the International Society of Ultrasound in Obstetrics and Gynecology 33 (5): 502–5. doi:10.1002/uog.6381.