汪国军. 阶n≤5的有条件(S)的BCK-代数[J]. 浙江大学学报(理学版), .
WANG Guo-jun . BCK-Algebras with Order n≤5.. Journal of Zhejiang University (Science Edition), .
https://www.zjujournals.com/sci/CN/ 或 https://www.zjujournals.com/sci/CN/Y1999/V26/I2/8
Cited