A concise monograph by two Russian experts provides an account of the operational calculus in two variables based on the two-dimensional Laplace transform. Suitable for advanced undergraduates and graduate students in mathematics, the treatment requires some familiarity with operational calculus in one variable. Part One of the two-part approach presents the fundamental theory in two chapters, examining the two-dimensional Laplace transform and offering basic definitions and theorems of the operational calculus in two variables and its applications. Part Two presents tables of formulae for various categories of functions, including rational and irrational functions; exponential and logarithmic functions; cylinder, integral, and confluent hypergeometric functions; and other areas. AUTHORS: Russian mathematician V. A. Ditkin (1910 86) served for many years on faculty of the Computing Centre of the Academy of Sciences of the U.S.S.R. A. P. Prudnikov (1927 99) was a Russian mathematician and a student of V. A. Ditkin. The two co-authored several handbooks on integral transforms and operational calculus.