Perhaps you should try some spelling variations:
"occasional letters; occasional letter" » "occasional notes; occasional letter", "occasional prayers; occasional letter", "occasional papers; occasional letter", "occasional verses; occasional verse", "occasional notess; occasional notes"
"occasional writer; occasional letter" » "occasional writer; occasional verse", "occasional writer; occasional notes", "occasional notes; occasional letter"
"occasions written; occasional letter" » "occasions written; occasional verse", "occasions written; occasional notes"

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: (("occasional letters; occasional letter") OR ((("occasional writer; occasional letter") OR ("occasions written; occasional letter")))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"occasional letters; occasional letter\") or (((\"occasional writer; occasional letter\") OR (\"occasions written; occasional letter\"))))".
• Removing quotes may allow a broader search: (( occasional letters; occasional letter ) or ((( occasional writer; occasional letter ) OR ( occasions written; occasional letter )))).
• Adding a wildcard symbol may retrieve word variants: (("occasional letters; occasional letter") or ((("occasional writer; occasional letter") OR ("occasions written; occasional letter"))))*.