Hermenegildo, Manuel V. and Bueno Carrillo, Francisco and Puebla Sánchez, Alvaro Germán and López García, Pedro (1999). Program analysis, debugging and optimization using the ciao system preprocessor. In: "The 1999 international conference on Logic programming", November 29 - December 4, 1999, Las Cruces, New Mexico, USA. ISBN 0262541041.