@article{SF_1986__34_134851,
     author = {T.V. Tonev},
     title = {Positive-definite functions on discrete commutative semigroups: {Errata} and supplements.},
     journal = {Semigroup forum},
     pages = {371--372},
     publisher = {mathdoc},
     volume = {34},
     year = {1986},
     zbl = {0609.20040},
     url = {http://geodesic.mathdoc.fr/item/SF_1986__34_134851/}
}