Gao and Lau Ka-Sing introduced James nonsquare constants and Schaffer constants, and in 1999, Ji Donghai and Wang Shuxin gave the defination of pointwise nonsquare constants.

• Gao 和Lau Ka-Sing 给出了James 非方常数C_J和Schaffe 非方常数C_S的定义,1999 年计东海和王淑欣引进了点态非方常数的概念。