A proof of J. Mařík's lemma

Instytut Matematyczny Polskiej Akademii Nauk / Institute of Mathematics / Publishing house / Journals and Serials / Colloquium Mathematicum / All issues

H. W. Pu, J. P. Spencer Colloquium Mathematicum 24 (1971), 85-88 DOI: 10.4064/cm-24-1-85-88