CRA Pub IC-86 4R3 Scientific Research and Experimental Development May 1994 [PDF] WARNING: This publication has been officially obsolete since Dec 2012, however given its historically wide acceptance by the courts as a frequently referenced authority, and that there have been no significant changes in the legislation with respect to scientific / technological eligibility criteria since then, it remains a potentially useful guidance document.
CRA Pub 97-1 SRED Admin Guidelines for Software Development Feb 1997 [PDF] WARNING: This publication is officially obsolete as of Dec 2012, however Exhibits A, B, D & D contained in it remain useful demarcations for the boundaries of SR&ED eligibility in the field of software development.