@article{IJAMCS_2002_12_3_a4,
     author = {Turksen, I. B.},
     title = {Upper and {Lower} {Set} {Formulas:} {Restriction} and {Modification} of the {Dempster-Pawlak} {Formalism}},
     journal = {International Journal of Applied Mathematics and Computer Science},
     pages = {359--369},
     publisher = {mathdoc},
     volume = {12},
     number = {3},
     year = {2002},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/IJAMCS_2002_12_3_a4/}
}