@article{10_14708_cm_v30i2_6318,
     author = {J. Grzybowski},
     title = {A note on (s,t)-convex modulars},
     journal = {Commentationes Mathematicae},
     pages = { 309--315},
     year = {1991},
     volume = {30},
     number = {2},
     doi = {10.14708/cm.v30i2.6318},
     language = {pl},
     url = {http://geodesic.mathdoc.fr/articles/10.14708/cm.v30i2.6318/}
}