@article{CSIS_2013_10_4_a2,
     author = {Wiktor Nowakowski and Micha{\l} Smia{\l}ek and Albert Ambroziewicz and Tomasz Straszak},
     title = {Requirements-Level {Language} and {Tools} for {Capturing} {Software} {System} {Essence}},
     journal = {Computer Science and Information Systems},
     publisher = {mathdoc},
     volume = {10},
     number = {4},
     year = {2013},
     url = {http://geodesic.mathdoc.fr/item/CSIS_2013_10_4_a2/}
}