@article{KYB_2004_40_4_a4,
     author = {Hong, Dug Hun},
     title = {On types of fuzzy numbers under addition},
     journal = {Kybernetika},
     pages = {469--476},
     year = {2004},
     volume = {40},
     number = {4},
     mrnumber = {2102365},
     zbl = {1249.03095},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/KYB_2004_40_4_a4/}
}