Perhaps you should try some spelling variations:
"occasional letters; occasional letter" » "occasional prayers; occasional letter", "occasional papers; occasional letter", "occasional verses; occasional verse"
"occasional writings; occasional writer" » "occasional writings; occasions written"
"occasional notess; occasional notes" » "occasional notices; occasional notes", "occasional poems; occasional notes", "occasion notes; 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 writings; occasional writer"))) OR ("occasional notess; occasional notes")).
• Removing quotes may allow a broader search: (((( occasional letters; occasional letter ) or ( occasional writings; occasional writer ))) or ( occasional notess; occasional notes )).
• Adding a wildcard symbol may retrieve word variants: (((("occasional letters; occasional letter") or ("occasional writings; occasional writer"))) or ("occasional notess; occasional notes"))*.