@article{JNSA_2018_11_7_a2,
     author = {Keltouma, Belfakih  and Elhoucien, Elqorachi  and Rassias, Themistocles M.  and Ahmed, Redouani },
     title = {Superstability of  {Kannappan's} and {Van} vleck's  functional equations },
     journal = {Journal of nonlinear sciences and its applications},
     pages = {894-915},
     publisher = {mathdoc},
     volume = {11},
     number = {7},
     year = {2018},
     doi = {10.22436/jnsa.011.07.03},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.22436/jnsa.011.07.03/}
}