@article{EUG_1995_42_a9,
     author = {Thomas Vougiouklis},
     title = {Fundamental {Relations} in {Hyperstructures}},
     journal = {E\ensuremath{\upsilon}\ensuremath{\kappa}\ensuremath{\lambda}\ensuremath{\varepsilon}\ensuremath{\acute\iota}\ensuremath{\delta}\ensuremath{\eta}\ensuremath{\varsigma} \ensuremath{\Gamma}},
     pages = {113--118},
     year = {1995},
     volume = {42},
     language = {gr},
     url = {http://geodesic.mathdoc.fr/item/EUG_1995_42_a9/}
}