Columbia subject headings:
Harvard subject headings:
Credit--Europe--History--Congresses.
Finance--Europe--History--Congresses.
Social networks--Europe--History--Congresses.
Princeton subject headings:
Credit--Europe--History--Congresses.
Credit--Social aspects--Europe--Congresses.
Debtor and creditor--Europe--History--Congresses.
Debtor and creditor--Social aspects--Europe--Congresses.
Social networks--Europe--History--Congresses.