These are some books written by members of the meetup.
Richard Cotton
Andrew Gelman & Deborah Nolan
JD Long
Hadley Wickham
JJ Allaire
Drew Conway & John Myles White
Mike Dewar
Rob Hyndman
Q. Ethan McCallum
Max Kuhn
David Robinson
Andrew Gelman
Harlan Harris, Sean Patrick Murphy & Marck Vaisman
Bryan Lewis and Michael Kane
John Myles White
Wes McKinney
Andrew Gelman, John B. Carlin, Hal S. Stern, David B. Dunson, Aki Vehtari & Donald B. Rubin
Daniel Y. Chen
Chris Fregly & Antje Barth
Hadley Wichkam
Max Kuhn & Kjell Johnson
Andrew Gelman & Jeronimo Cortina
Tony Fischetti
Julia Silge & David Robinson
Cathy O'Neil & Rachel Schutt
Jeroen Janssens
Jared P. Lander
Paul Dix
Andrew Gelman & Jennifer Hill