1. D. E. Knuth, The Art of Computer Programming, Semi numerical Algorithms, Adison- Wesley, 2, (1981).
2. Relations and functions in multiset context
3. K. P. Girish and S.J. John, Rough Multiset and its Multiset Topology, Lecture Notes in Computer Science, Springer. Berlin, Heidelberg, 6600, 62–80, (2011)
4. K. P. Girish and S.J. John, On multiset topologies, Theory Appl. Math. Comput. Sci., 2, 37–52, (2012).
5. Multiset topologies induced by multiset relations