@article{BSL2_1_Pirog-Rzepecka,
author = {Krystyna PIR{\'O}G-RZEPECKA},
title = {A Predicate Calculus with Formulas Which Lose Sense and the Corresponding Propositional Calculus},
journal = {Bulletin of the Section of Logic},
volume = {2},
number = {1},
year = {1973},
pages = {22--29}
}