Perhaps you should try some spelling variations:
occasional letters » occasional notes, occasional writer, occasional prayers
occasional letter » occasional writer, occasional verse, occasional notes
2f number » 2 number, 22 number, 23 number
21 number » 2 number, 1 number, 22 number

Try widening your search to All Fields.

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: %((((22occasional letter) OR (occasional letters))) OR (occasional letter)) %((2f number) OR (21 number)) 1%22.
• The words AND, OR and NOT may confuse the search; try adding quotes: "%((((22occasional letter) OR (occasional letters))) or (occasional letter)) %((2f number) or (21 number)) 1%22".
• Adding a wildcard symbol may retrieve word variants: %((((22occasional letter) OR (occasional letters))) or (occasional letter)) %((2f number) or (21 number)) 1%22*.