Perhaps you should try some spelling variations:
"ruusbroec, jean a / 1293-1381" » "ruusbroec, jean _ / 1293-1381", "ruusbroec, jean c / 1293-1381"
"ruusbroec, jean d / 1293-1381" » "ruusbroec, jean de / 1293-1381", "ruusbroec, jean _ / 1293-1381"

Try widening your search to All Fields.

You may be able to get more results by adjusting your search query.

• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"ruusbroec, jean a / 1293-1381\") OR (\"ruusbroec, jean d / 1293-1381\"))".
• Removing quotes may allow a broader search: (( ruusbroec, jean a / 1293-1381 ) OR ( ruusbroec, jean d / 1293-1381 )).
• Adding a wildcard symbol may retrieve word variants: (("ruusbroec, jean a / 1293-1381") OR ("ruusbroec, jean d / 1293-1381"))*.