Shirley L. Green, a freelance researcher who used her access to photo repositories throughout Washington to help scholars, publishers, filmmakers, TV producers, advertisers and others looking for vintage photographic images, died May 1 in Bethesda. She was 91.

She had congestive heart failure and died at the Maplewood Park Place retirement community, said her daughter Stephanie G. Lawson.

In a career spanning five decades, Mrs. Green became a leading scavenger of photographic images in the public domain. In 1976, she revealed in her book “Pictorial Resources in the Washington, D.C., Area,” the best-kept secrets of her trade, alerting readers to the government agencies, international organizations and private groups that furnish photographs at often far less cost than prestigious repositories such as the Bettmann Archive.

Among the projects she conducted photographic research for were the 25-volume “The Vietnam Experience” edited in the 1980s by Robert Manning, a former assistant secretary of State and editor of the Atlantic; the Peabody Award-winning documentary “Normandy: The Great Crusade” (1994); and Oliver Jensen’s 1978 book “America’s Yesterdays: Images of Our Lost Past Discovered in the Photographic Archives of the Library of Congress.”

She also partnered with her niece, historian Jane Freundel Levey, on a five-part series of photo essays called “Photodiscovery” that was published in The Washington Post Magazine in 1979.

Shirley Lillian Freundel was born in Brooklyn, N.Y., to Jewish immigrants from Eastern Europe. She was seventh of eight children. She was a 1941 history graduate of Brooklyn College and settled in the Washington area during World War II.

She worked at the Library of Congress from 1948 to 1951, becoming a processor of visual materials in the prints and photographs division. She turned freelance while raising her children and retired in 1998.

A longtime Bethesda resident, she was a Montgomery County precinct chair for the Democratic Party. In the early 1960s, she was a leader in the desegregation of the Old Georgetown Swim and Tennis Club in Bethesda, Levey said.

Her husband of 62 years, Paul S. Green, died in 2008. Besides her daughter, of Bethesda, survivors include another daughter, Deborah G. Latimer of McLean, and four granddaughters.

— Adam Bernstein