Monthly, 1997-, Bimonthly, 1988-1994, and 8 no. a year, 1995-1996
Title from cover. and This title is included in a commitment Penn State made in 2009 to archive specified science journals in print format as a back-up for their online availability under the PALCI Distributed Print Archive agreement; holdings located at University Park campus are not to be withdrawn.
Some issues accompanied by supplementary material on microfiche.
Issues for <1994-> published with the cooperation of the International Society for the Study of Xenobiotics.