@article{10_4064_ap_51_1_7_13,
     author = {Andrzej Lasota and Czes{\l}aw Olech},
     title = {Zdzis{\l}aw {Opial---a} mathematician 1930--1974},
     journal = {Annales Polonici Mathematici},
     pages = {7--13},
     year = {1990},
     volume = {51},
     number = {1},
     doi = {10.4064/ap-51-1-7-13},
     language = {pl},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/ap-51-1-7-13/}
}