@article{SMJ2_2001_27_3_a1,
     author = {Ivanov, Vsevolod},
     title = {First {Order} {Characterizations} of {Pseudoconvex} {Functions}},
     journal = {Serdica Mathematical Journal},
     pages = {203--218},
     publisher = {mathdoc},
     volume = {27},
     number = {3},
     year = {2001},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SMJ2_2001_27_3_a1/}
}