@article{NSJOM_2006_36_1a_6,
     author = {M. Masal},
     title = {(m+1)-dimensional spacelike parallel $p_i$-equidistant ruled surfaces in the {Minkowski} space $R_1^n $},
     journal = {Novi Sad Journal of Mathematics},
     pages = {55-63},
     publisher = {mathdoc},
     volume = {36},
     number = {1},
     year = {2006},
     url = {http://geodesic.mathdoc.fr/item/NSJOM_2006_36_1a_6/}
}