Brown, W. S., Hyde, J. P., and Tague, B.A. "The ALPAK system for non-numerical algebra on a digital computer - II. Rational functions of several variables and truncated power series with rational-function coefficients"

(1964) Bell System Technical Journal 43(2) March 1964  

Languages mentioned ALPAK {1963} Extension to ALTRAN to manipulate polynomials and rational functions