@article {IOPORT.03804920,
    author       = {Beniaminov, E.M.},
    title        = {An algebraic approach to models of data bases of the relational type.},
    year         = {1980},
    journal      = {Semiotika i Informatika.},
    volume       = {14},
    pages        = {44-80},
    publisher    = {VINITI, Moskva},
    identifier   = {03804920},
}