This routine should be called prior to importing any document information
to the LBS with the function lbsImportDocuments.If multiple sources with the same ISSN (either Print-ISSN or E-ISSN)
are found in Scopus_SourceList
and updateSourceIfExists is FALSE, then
only the first matching record is added to the table Biblio_Sources.
Additionally, a warning is generated.
Otherwise, the last non-unique record is taken into account.
Note that adding all the sources takes some time.
Only basic ASJC and SciVerse Scopus source information
retrieved from Scopus_ASJC (stored in the table Biblio_Categories)
and Scopus_SourceList (stored in tables Biblio_Countries and Biblio_Sources)
will be added to the LBS.