Taking on Viagra.
Simons
John
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D000329:Advertising; D000375:Aging / Q000502:physiology; D019049:Developed Countries; D004345:Drug Industry / Q000191:economics; D007172:Erectile Dysfunction / Q000188:drug therapy* / Q000453:epidemiology; D006801:Humans; D008297:Male; D010879:Piperazines / Q000627:therapeutic use; D011687:Purines; D000068677:Sildenafil Citrate; D013450:Sulfones; D014481:United States / Q000453:epidemiology
D010879:Piperazines; D011687:Purines; D013450:Sulfones; D000068677:Sildenafil Citrate