참고문헌
- S.S. Ahn & K.S. So: On ideals and upper sets in BE-algerbas, Sci. Math. Jpn. 68 (2008), 279-285.
- H.S. Kim & Y.H. Kim: On BE-algerbas. Sci. Math. Jpn. 66 (2007), 113-116.
- A. Walendziak: On commutative BE-algerbas. Sci. Math. Jpn. 69 (2007), 281-284.