In science, the question of who gets credit for important work—fraught in any field—is set down on paper, for anyone to see. Authorship, given pride of place at the top of scientific papers, can advance reputations and careers; credits buried in the rarely read acknowledgments section do not.

Over the past few years, a team of students led by Emilia Huerta-Sánchez from Brown University and Rori Rohlfs from San Francisco State University have been searching through two decades’ worth of acknowledgments in genetics papers and discovering women who were never given the credit that would be expected for today’s researchers. They identified dozens of female programmers who made important but unrecognized contributions. Some were repeatedly thanked in the acknowledgments of several papers, but were never recognized as authors. They became literal footnotes in scientific history, despite helping make that history.

“When Emilia and I look at our elders in population genetics, there are very, very few women,” says Rohlfs. “But there were women and they were doing this work. To even know that they existed is a big deal to me.”