@inbook{inbook6be33ff9,
title   = {A method and a program for the school timetabling problem},
author = {Ribeiro, Cassilda Maria and Santos, Lana Mara Rodrigues dos and Ferreira Ribeiro, José Francisco},
year = {1999},
publisher = {WSES},
journal   = {Software and hardware engineering for the 21th century}
}