R. M. Green is a Professor in the Department of Mathematics at the University of Colorado, Boulder. He is the author of about 50 papers, many of which concern the combinatorics of Coxeter groups and related topics.
'This monograph could be read with profit not only by the specialist, but also by an interested graduate student with some background on Lie algebras.' Felipe Zaldivar, MAA Reviews (maa.org/publications/maa-reviews)