Abstract :
This index covers all items that appeared in this periodical during 1991, and items from previous years that were commented upon or corrected in 1991. The Author Index contains the primary entry for each item, listed under the first author´s name, and cross-references from all coauthors. The Subject Index contains several entries for each item under appropriate subject head?? ings, and subject cross-references. It is always necessary to refer to the primary entry in the Author Index for the exact title, coauthors, and comments/corrections.
