@article{BSL8_3_Andreka_Nemeti_Sain,
author = {Hajnal ANDR{\'E}KA and Istv{\'a}n N{\'E}METI and Ildik{\'o} SAIN},
title = {Program Verification Within and Without Logic},
journal = {Bulletin of the Section of Logic},
volume = {8},
number = {3},
year = {1979},
pages = {124--129}
}