T. R. Razak, S. S. Mohd Fauzi, R. A. JM Gining, M. H. Ismail, and R. Maskat, “Hierarchical Fuzzy Systems: Interpretability and Complexity”, IJEEI, vol. 9, no. 2, pp. 478–489, Jun. 2021, doi: 10.52549/ijeei.v9i2.2813.