Heinen, T., Jeraj, D., Vinken, P. M., Knieps, K., Velentzas, K., & Richter, H. (2011). What it takes to do the double jaeger on the high bar? Science of gymnastics journal, 3(3), S. 7-18. http://www.google.de/url?sa=t&rct=j&q=&esrc=s&source=web&cd=2&ved=0CCcQFjAB&url=http%3A%2F%2Fwww.fsp.uni-lj.si%2Fmma_bin.php%3Fid%3D20111001004122&ei=H-UrVJuwKcjJOdTJgOgL&usg=AFQjCNF97WnOYFA_b-zzNL0dCmGGAwWU6g&bvm=bv.76477589,d.ZWU

Heinen, Thomas, Damian Jeraj, Pia Maria Vinken, Katharina Knieps, Konstantinos Velentzas, and Hedi Richter. "What It Takes to Do the Double Jaeger On the High Bar?" Science of Gymnastics Journal 3, no. 3 (2011): S. 7-18.

Heinen, Thomas, et al. "What It Takes to Do the Double Jaeger On the High Bar?" Science of Gymnastics Journal 3.3 (2011): S. 7-18.