Brian W. Kernighan and Dennis M. Ritchie. The m4 macro processor. Technical report, Bell Laboratories, Murray Hill, New Jersey, USA, 1977. pdfArchived August 5, 2004, at the Wayback Machine
Kenneth J. Turner. Exploiting the m4 macro language. Technical Report CSM-126, Department of Computing Science and Mathematics, University of Stirling, Scotland, September 1994. pdf
Brian W. Kernighan and Dennis M. Ritchie. The m4 macro processor. Technical report, Bell Laboratories, Murray Hill, New Jersey, USA, 1977. pdfArchived August 5, 2004, at the Wayback Machine