The phrase "a rich source for" is correct and usable in written English.
It can be used when referring to something that provides a lot of valuable information or material on a particular topic.
Example: "The internet is a rich source for research materials on various subjects."
Alternatives: "a valuable resource for" or "an abundant supply of".
Science has always been a rich source for those ideas.
The manager's cringeworthy video will be a rich source for parody for years to come.
"Madame X," described by Sargent in 1916 as his finest work, has provided a rich source for inspiration.
Their letters dealt with spiritual and political matters and form a rich source for historians on Philip's reign.
His Correspondence, containing more than 160 letters, is a rich source for knowledge of the outstanding Byzantine ecclesiastical and political figures of the period.
Material for the Arts, the city's program that offers castoff materials, furniture and supplies to nonprofit arts organizations, has been a rich source for them.
The famine has been a rich source for scientists — a controlled experiment in what happens when a normally well-nourished population is deprived of food for a sustained but limited period of time.
Memories are a rich source for writers, but as White himself explained in the epigraph to Sims's book, "Real life is only one kind of life — there is also the life of the imagination".
For all that he's rarely credited, one of the busiest screenwriters in Bollywood is William Shakespeare, whose plotlines and characters have proven to be a rich source for popular Hindi film for over a century.
But even in its less honorable forms, anime has proven to be a rich source for cultural anthropologists, who find in it a vivid illustration of the dissolving identities and collapsing institutions that characterize life in postmodernist cultures.
It's a rich source for mentors and advisors.
