John N. Mordeson, Kiran R. Bhutani, Azriel Rosenfeld. Fuzzy Group Theory. Volume 182 of Studies in Fuzziness and Soft Computing, Springer, 2005. [doi]
@book{MordesonBR05,
title = {Fuzzy Group Theory},
author = {John N. Mordeson and Kiran R. Bhutani and Azriel Rosenfeld},
year = {2005},
doi = {10.1007/b12359},
url = {http://dx.doi.org/10.1007/b12359},
researchr = {https://researchr.org/publication/MordesonBR05},
cites = {0},
citedby = {0},
volume = {182},
series = {Studies in Fuzziness and Soft Computing},
publisher = {Springer},
isbn = {978-3-540-25072-2},
}