@article{BSL9_3_Dziobiak,
author = {Wies{\l}aw DZIOBIAK},
title = {The Degrees of Maximality of the Intuitionistic Propositional Logic and of Some of Its Fragments},
journal = {Bulletin of the Section of Logic},
volume = {9},
number = {3},
year = {1980},
pages = {136--140}
}