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

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 periodical returns ) OR ( specialist period returns )))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( specialist periodical vendors ) or ((( specialist periodical returns ) OR ( specialist period returns ))))".
• Adding a wildcard symbol may retrieve word variants: (( specialist periodical vendors ) or ((( specialist periodical returns ) OR ( specialist period returns ))))*.