@techreport{plt-tr2009-r6rs-v4.1.5, author = {PLT}, title = {{R6RS}: Standard Language}, number = {PLT-TR2009-r6rs-v4.1.5}, type = {Reference Manual}, institution = {PLT Scheme Inc.}, month = {March}, year = {2009}, url = {http://download.plt-scheme.org/doc/4.1.5/pdf/r6rs.pdf}, note = {\url{http://plt-scheme.org/techreports/}; See also: Michael Sperber and R. Kent Dybvig and Matthew Flatt and Anton Van Straaten (Editors) Revised$^6$ Report of the Algorithmic Language Scheme September 2007} }