You may already know about this, but there is a listserv for back
issues of serials wherein libraries can exchange duplicate issues
with each other to replace each other's missing issues.  All you
pay typically is the cost of postage.  The address to subscribe to is
listserv@sun.readmore.com.  Send them the message "Subscribe Backserv
(your name)" to get in on the action.

From:    Ingrid Grimes <lgrimes@PEACE.EDU>