@article{NSJOM_1990_20_1a_7,
     author = {Pap Endre},
     title = {Distance preserving maps 

 on abelian lattice ordered groups},
     journal = {Novi Sad Journal of Mathematics},
     pages = {75-82},
     publisher = {mathdoc},
     volume = {20},
     number = {1},
     year = {1990},
     url = {http://geodesic.mathdoc.fr/item/NSJOM_1990_20_1a_7/}
}