I first learned about Paula Modersohn-Becker in graduate school.  At the time, I was only aware of a couple books about her. One was actually a publication of her letters/journals and it contained no images.  It is amazing and should be required reading for anyone interested in the struggle of painters to learn and grow and especially of women artists to be seen as equal to their male counterparts. The other was a nice little book by Gillian Perry that had a limited number of small scale reproductions.  Recently I became aware of two new books on Modersohn-Becker, one is the catalog for a show at the Louisiana Museum of Modern Art in Copenhagen and the other a monograph by Diane Radycki.  Both are worthwhile and have more and better reproductions than any book I have seen up to this point.  The Radycki book is especially good not only for the images, but for the writing.  Modersohn-Becker was a great painter and still under-appreciated, in my opinion.