Weighted Trapezoidal Approximations of Fuzzy Numbers. - Przemyslaw Grzegorzewski; Karolina Pasternak-Winiarska (IFSA/EUSFLAT Conf., 2009)

Bi-symmetrically Weighted Trapezoidal Approximations of Fuzzy Numbers. - Przemyslaw Grzegorzewski; Karolina Pasternak-Winiarska (ISDA, 2009)

Trapezoidal approximations of fuzzy numbers with restrictions on the support and core. - Przemyslaw Grzegorzewski; Karolina Pasternak-Winiarska (EUSFLAT Conf., 2011)

Natural trapezoidal approximations of fuzzy numbers. - Przemyslaw Grzegorzewski; Karolina Pasternak-Winiarska (Fuzzy Sets Syst., 2014)