I was reading through the entry to ἄρχων, and it states under 2 A:
ⓐ of Jewish leaders (Schürer.....
Now it so happens this Schurer reference is, if you check the biblio, "A History of the Jewish People in the Time of Jesus Christ (4 volumes), which is also a Logos resource now.
Should BDAG be updated to make this a link to this resource? Are there other resources in BDAG that are not linked?
BDAG has an incredible bibliography, it would be great if all Logos resources are covered. I don't know how many are missing.