How Viagra was discovered by Pfizer

Botox, meet Viagra: Biggest health care deal of Allergan-Pfizer would have to pass antitrust muster – Orange County Register

History of Viagra and how it was discovered by accident

Drugs that treat erectile dysfunction could help reduce risk of Alzheimer's, U.K. study says - CBS Boston

20 Years Later, Viagra Means Something Different For Millennials

Viagra: The Happiest of All Happy Accidents? - Longreads

Bashful? Pfizer to begin selling Viagra directly to patients online – New York Daily News

Can Viagra Prevent Alzheimer's?

Lesser-known facts about Viagra as the 'little blue pill' turns 20 – New York Daily News

Facing Off Against Counterfeit Online Pharmacies: Pfizer Launches New Purchasing Website To Help Alleviate the Guesswork Around Buying Legitimate Viagra® (sildenafil citrate) Online

Viagra Goes Generic: Pfizer to Launch Own Little White Pill - Drug Discovery and Development

Viagra and many other drugs were discovered by chance. Now science is hoping to change that. - The Washington Post

How Viagra Was Discovered By Accident Viagra: The Little Blue Pill That Changed The World