Perhaps you should try some spelling variations:
15 matthew » _ matthew, dr matthew, 8 matthew
21 sermons » 1 sermons, 14 sermons, 8 sermons
6 matthew » _ matthew, 8 matthew, dr matthew
6 sermons » 1 sermons
22 early » 2 early, 12 early, 1722 early
2c 51 » 24 51, c 51, 20 51

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

• If you are trying to use Boolean operators, they must be ALL CAPS: %22bible %2f n.t %((15 matthew) OR (6 matthew)) xxviii%2c 51 %((21 sermons) OR (((6 sermons) OR (2 sermons)))) %22 early works to 1800%22.
• The words AND, OR and NOT may confuse the search; try adding quotes: "%22bible %2f n.t %((15 matthew) or (6 matthew)) xxviii%2c 51 %((21 sermons) or (((6 sermons) OR (2 sermons)))) %22 early works to 1800%22".
• Adding a wildcard symbol may retrieve word variants: %22bible %2f n.t %((15 matthew) or (6 matthew)) xxviii%2c 51 %((21 sermons) or (((6 sermons) OR (2 sermons)))) %22 early works to 1800%22*.