APA

Hsu A. R., Barnholt K. E., Grundmann N. K., Lin J. H., McCallum S. W. & Friedlander A. L. (20060804). Sildenafil improves cardiac output and exercise performance during acute hypoxia, but not normoxia. : Journal of applied physiology (Bethesda, Md. : 1985).

Chicago

Hsu Andrew R, Barnholt Kimberly E, Grundmann Nicolas K, Lin Joseph H, McCallum Stewart W and Friedlander Anne L. 20060804. Sildenafil improves cardiac output and exercise performance during acute hypoxia, but not normoxia. : Journal of applied physiology (Bethesda, Md. : 1985).

Harvard

Hsu A. R., Barnholt K. E., Grundmann N. K., Lin J. H., McCallum S. W. and Friedlander A. L. (20060804). Sildenafil improves cardiac output and exercise performance during acute hypoxia, but not normoxia. : Journal of applied physiology (Bethesda, Md. : 1985).

MLA

Hsu Andrew R, Barnholt Kimberly E, Grundmann Nicolas K, Lin Joseph H, McCallum Stewart W and Friedlander Anne L. Sildenafil improves cardiac output and exercise performance during acute hypoxia, but not normoxia. : Journal of applied physiology (Bethesda, Md. : 1985). 20060804.