1. Some results about the number of jumps in acircuit digraphs;Chaty, G.,1974
2. Sur le nombre de sauts d’une forêt;Chein, Michel;C. R. Acad. Sci. Paris S\'{e}r. A-B,1972
3. The jump number of dags and posets: an introduction;Chein, M.;Ann. Discrete Math.,1980
4. Nombre de sauts et graphes série-parallèles;Cogis, O.;RAIRO Inform. Th\'{e}or.,1979
5. A decomposition theorem for partially ordered sets;Dilworth, R. P.;Ann. of Math. (2),1950