Version 2.90 includes a new general search tool that comes as a replacement for the old limited "author search" tool.
The search dialog is opened by going to the Search->Request menu item. A search request follows the general form:
FIELD_TYPE matching operator REGEXP
Several expression separated by a Boolean operator ('|' OR or '&' AND) are allowed, and priority may be specified by parenthesis. Here is an example:
(AUTHOR=Kimura | AUTHOR=Tamura) & YEAR=19\d\d
Search for all entries with author "Kimura" or "Tamura" published in the XXth century.
Finally, the request dialog provides some shortcuts for typing the request.