penis enlargement

"Although it is well known that penile growth is dependent on androgens, few clinical studies have reported successful treatment of micropenis with testosterone, likely due to concerns regarding the efficacy and safety of prolonged testosterone use. Thus, we assessed the synergistic effects of...

So I see on this site tools and surgeries etc and things to increase penis size and etc etc...but what about the manual exercises that guys swear by that it works. All the exercises like at www.PEgym.com have there been any studies at all on manual enlargement in girth and length by doing these...