Wang, P.Z.Lee, E.S.Tan, S.K.MATHEMATICS2014-10-282014-10-281991-09-15Wang, P.Z.,Lee, E.S.,Tan, S.K. (1991-09-15). A combinatoric formula. Journal of Mathematical Analysis and Applications 160 (2) : 500-503. ScholarBank@NUS Repository.0022247Xhttps://scholarbank.nus.edu.sg/handle/10635/102619A combinatoric formulaArticleNOT_IN_WOS