Re definition of Serial
     For our purposes:
        Serial-a publication issued in successive parts and normally intended t
o continue indefinitely.  As a rule serials have a common title and their jpart
s are sequentially related by a numbering or lettering scheme.
            Continuation-an irregular serial (not issued at stated or regular i
ntervals) or one issued at intervals of a half year or more.
            Periodical-a serial which is intended to be issued at stated or reg
ular intervals, such intervals must be less than one half year, or which has "j
ournal" in its title.