@article {IOPORT.06080604,
    author       = {Kim, Yong Chan},
    title        = {Soft lower and upper approximations.},
    year         = {2012},
    journal      = {International Journal of Contemporary Mathematical Sciences},
    volume       = {7},
    number       = {13-16},
    issn         = {1312-7586},
    pages        = {641-648},
    publisher    = {Hikari Ltd, Ruse},
    abstract     = {Summary: We introduce the notion of soft $(\underline {apr}_P, \overline {apr}_P)$ (respectively $(\underline {Apr}_P, \overline {apr}_P)$, $(\underline {apr}_P, \overline {Apr}_P)$, $(\underline {Apr}_P,\overline {Apr}_P)$) rough approximations.},
    identifier   = {06080604},
}