@InCollection{nel,
author = {Till Mossakowski and Joseph Goguen and R\u{a}zvan Diaconescu and Andrzej Tarlecki},
title = {What is a Logic?},
booktitle = {Logica Universalis},
pages = {113--133},
publisher = {Birkh\"{a}user},
year = 2005,
editor = {Jean-Yves B\'{e}ziau}
}