Columbia subject headings:
Book industries and trade--Latvia--History--Congresses.
Printing--Latvia--History--Congresses.
Publishers and publishing--Latvia--History--Congresses.
Harvard subject headings:
Book industries and trade--Latvia--History--Congresses.
Printing--Latvia--History--Congresses.
Publishers and publishing--Latvia--History--Congresses.
Princeton subject headings:
Book industries and trade--Latvia--History--Congresses.
Printing--Latvia--History--Congresses.
Publishers and publishing--Latvia--History--Congresses.