[1] J. Ad´amek, H. Herrlich and G. E. Strecker, Abstract and concrete categories, Wiley, New
York, 1990.
[2] K. R. Bhutani, J. Mordeson and A. Rosenfeld, On degrees of end nodes and cut nodes in
fuzzy graphs, Iranian Journal of Fuzzy Systems, 1 (2004), 57-64.
[3] J. Edmonds, Matroids and the greedy algorithm, Mathematical Programming, 1 (1971), 125-
136.
[4] D. Gale, Optimal assignments in an ordered set: an application of matroid theory, Journal
of Combinatoral Theory, 4 (1968), 176-180.
[5] R. Goetschel and W. Voxman, Bases of fuzzy matroids, Fuzzy Sets and Systems, 31 (1989),
253-261.
[6] R. Goetschel and W. Voxman, Fuzzy circuits, Fuzzy Sets and Systems, 32 (1989), 35-43.
[7] R. Goetschel and W. Voxman, Fuzzy matroids, Fuzzy Sets and Systems, 27 (1988), 291-302.
[8] R. Goetschel and W. Voxman, Fuzzy rank functions, Fuzzy Sets and Systems, 42 (1991),
245-258.
[9] S. G. Li, X. Xin and Y. L. Li, Closure axioms for a class of fuzzy matroids and the co-tower
of matroids, Fuzzy Sets and Systems, 158 (2007), 1246-1257.
[10] J. G. Oxley, Matroid Theory, Oxford Universty Press, 1992.
[11] F. G. Shi, A new approach to the fuzzification of matroids, Fuzzy Sets and Systems, 160
(2009), 696-705.
[12] M. S. Ying, A new approach to fuzzy topologies (I), Fuzzy Sets and Systems, 39 (1991),
373-380.