@article{EUG_1996__46_a5,
     author = {Florian Luca},
     title = {On the {Sum-of-Divisors} {Function} of the {Numbers} of {Fermat} and {Ferentinou-Nicolacopoulou}},
     journal = {E\ensuremath{\upsilon}\ensuremath{\kappa}\ensuremath{\lambda}\ensuremath{\varepsilon}\ensuremath{\acute\iota}\ensuremath{\delta}\ensuremath{\eta}\ensuremath{\varsigma} \ensuremath{\Gamma}
},
     pages = {11-21},
     publisher = {mathdoc},
     volume = {46},
     year = {1996},
     language = {gr},
     url = {http://geodesic.mathdoc.fr/item/EUG_1996__46_a5/}
}