@article{BSL9_4_Krzystek,
author = {Piotr S. KRZYSTEK},
title = {Equivalential Fragment of the Infinite Valued Logic of Łukasiewicz and the Intermediate Logics},
journal = {Bulletin of the Section of Logic},
volume = {9},
number = {4},
year = {1980},
pages = {170--175}
}