Science and technology are upending how we learn. We separate the science from the snake oil and look at how parents, teachers, and policymakers respond.

Twitter may be the last place most people turn for wisdom, but sometimes a simple tweet can unleash a wealth of sage advice. Just in time for National Book Lovers’ Day, the Aug. 9 holiday mostly celebrated through hashtags and emojis, Susan Dynarski, a professor of public policy, economics, and education at the University of Michigan, posed a question to the Twitterverse:

Dynarski tells Quartz she was “curious about what gets people to choose doctoral studies, which is a huge commitment of time and energy. Did they want to fix a problem in public policy? Solve a theoretical puzzle?”

Professors, doctors, and PhD candidates obliged, with replies about the reading material that inspired them to pursue their degrees.

Replies came from the field of education…

…from political scientists and public policy experts…

…a historian…

…a psychologist…

…some from the world of science and math…

…a lot of sociologists…

…and even more economists, likely due to nature of social networks and Dynarski’s own area of study…

While most brought up serious academic works read during their undergraduate years, some reached further back into their past.

As for Dynarski herself, she tells Quartz, “I had been a union organizer for years, and I was a first-generation college graduate. While I was working on a master’s in public policy in the early ’90s, I read the emerging literature on income equality. I realized economists studied the problems I was trying to solve and so decided to apply to doctoral programs.”