APA (7th ed.) Citation

lh, Robert, & Groppel. World-class tennis technique.

Chicago Style (17th ed.) Citation

lh, Robert, and Groppel. World-class Tennis Technique. ChampaignlbHuman kineticslc2001.

MLA (9th ed.) Citation

lh, et al. World-class Tennis Technique.

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