Columbia subject headings:
Belgium--Church history.
Catholic Church--Belgium--Nivelles--Liturgy--History.
Catholic Church. Liber ordinarius (Saint Gertrude Abbey, Nivelles, Belgium)
Church history--Middle Ages, 600-1500.
Convents--Belgium--Nivelles--History--Sources.
Convents--Belgium--Nivelles--History.
Gertrude, of Nivelles, Saint, 626-659--Cult.
Monasticism and religious orders for women--Belgium--History--Sources.
Monasticism and religious orders for women--Belgium--History.
Religious architecture--Belgium--Nivelles--History.
Saint Gertrude Abbey (Nivelles, Belgium)--History.
Harvard subject headings:
Architecture--History
Belgium--Church history
Convents--Belgium--History.
Houghton Library. Manuscript. MS Lat 422.
Monasticism and religious orders for women--Belgium--History.
Princeton subject headings:
Belgium--Church history.
Catholic Church--Belgium--Nivelles--Liturgy--History.
Catholic Church. Liber ordinarius (Saint Gertrude Abbey, Nivelles, Belgium)
Church history--Middle Ages, 600-1500.
Convents--Belgium--Nivelles--History--Sources.
Convents--Belgium--Nivelles--History.
Gertrude, of Nivelles, Saint, 626-659--Cult.
Monasticism and religious orders for women--Belgium--History--Sources.
Monasticism and religious orders for women--Belgium--History.
Religious architecture--Belgium--Nivelles--History.
Saint Gertrude Abbey (Nivelles, Belgium)--History