The SMART system ftp://ftp.cs.cornell.edu/pub/smart/smart.11.0.tar.z See, among others, the various files in smart.11.0/Doc/howto/ and smart.11.0/Doc/overview/
SMART Tutorial for beginners. Written and maintained by Hans Paijmans http://pi0959.kub.nl:2080/Paai/Onderw/Smart/hands.html
Indexing Texts with SMART, by Hans Paijmans Linux Gazette Issue #13 January, 1997 http://www.linux.nu/www.linuxgazette.com/issue13/smart.html
Blair, D.C.; Maron, M.E., An evaluation of retrieval effectiveness for a full-text document retrieval system, Communications of the ACM V28:3, 1985, pp. 289-299. http://www.acm.org/pubs/citations/journals/cacm/1985-28-3/p289-blair/
G. Salton and M.J. McGill, Introduction to Modern Information Retrieval New York [etc.] : McGraw-Hill, 1983. (unavailable in librairies nor online; try your local university)
C.J. "Keith" van Rijsbergen,
Information Retrieval (online book), 2nd edition, 1979.
http://www.dcs.gla.ac.uk/Keith/Preface.html
http://www.iro.umontreal.ca/ nie/IR-book/Preface.html