@article{SJC_2007_1_3_a2,
     author = {Dimov, Aleksandar and Ilieva, Sylvia},
     title = {Generalized {Nets} {Model} of an {E-Learning} {System} {Software} {Architecture}},
     journal = {Serdica Journal of Computing},
     pages = {255--266},
     publisher = {mathdoc},
     volume = {1},
     number = {3},
     year = {2007},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SJC_2007_1_3_a2/}
}