Perhaps you should try some spelling variations:
"specialist periodical vendors" » "specialized periodicals vendors", "socialism periodicals vendors", "specialist medical vendors", "specialist periodical error", "specialist periodical record", "socialist periodical vendors", "special periodical vendors", "specialist speciesical vendors"
"specialist period returns" » "socialist period returns", "special period returns", "specialist species returns", "specialist periodical returns"

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: (("specialist periodical vendors") OR ("specialist period returns")).
• Removing quotes may allow a broader search: (( specialist periodical vendors ) or ( specialist period returns )).
• Adding a wildcard symbol may retrieve word variants: (("specialist periodical vendors") or ("specialist period returns"))*.