Perhaps you should try some spelling variations:
"occasional letters; occasional letter" » "occasional notes; occasional letter", "occasional writer; occasional letter", "occasional writers; occasional writer", "occasional notess; occasional notes"
"occasional prayers; occasional letter" » "occasional poems; occasional letter", "occasional writer; occasional letter", "occasional prayers; occasional writer", "occasional prayers; occasional notes"
"occasional prayers; occasional verse" » "occasional poems; occasional verse", "occasional writer; occasional verse"
"occasional papers; occasional letter" » "occasional papers; occasional writer", "occasional papers; occasional notes", "occasional paper; occasional letter", "occasional poems; occasional letter", "occasional notes; occasional letter"

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 papers; occasional letter"))) OR ((("occasional prayers; occasional letter") OR ("occasional prayers; occasional verse"))))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((\"occasional letters; occasional letter\") or (\"occasional papers; occasional letter\"))) or (((\"occasional prayers; occasional letter\") OR (\"occasional prayers; occasional verse\"))))*".
• Removing quotes may allow a broader search: (((( occasional letters; occasional letter ) or ( occasional papers; occasional letter ))) or ((( occasional prayers; occasional letter ) OR ( occasional prayers; occasional verse ))))*.