HELLRIEGEL. creator S.l.] Addison Wesley Longman Publishing Co 1992 6th ed. 1 v. (unpaged) HELLRIEGEL. 0201526026 (paperback) 9780201526028 (paperback) http://www.amazon.com/exec/obidos/ASIN/0201526026/chopaconline-20 http://www.amazon.com/exec/obidos/ASIN/0201526026/chopaconline-20