A contribution to the development of ALGOL
Niklaus Wirth, C. A. R. Hoare · Communications of the ACM · 1966
A programming language similar in many respects to ALGOL 60, but incorporating a large number of improvements based on six years' experience with that language, is described in detail.Part I consists of an introduction to the new language and a summary of the changes made to ALGOL 60, together with a discussion of the motives behind the revisions.Part II is a rigorous definition of the proposed language.Part III describes a set of proposed standard procedures to be used with the language, including facilities for input/output.