四值命题演算与四色问题(英文)

胡世华;陈强业

A NOTE ON THE 4-VALUED PROPOSITIONAL CALCULUS AND THE FOUR COLOUR PROBLEM

SHIH-HUA HOO(1);CHIANG-YE

数学学报 . 1951, (3): 243 -246 . DOI: 10.12386/A1951sxxb0011