Perhaps you should try some spelling variations:
"human bees periodicals." » "human diabetes periodicals.", "human indexes periodicals.", "human devices periodicals.", "human bites periodicals.", "human beast periodicals.", "human bones periodicals."
"human gas periodicals." » "human foods periodicals.", "human birds periodicals.", "human gwas periodicals.", "human gis periodicals.", "human grasp periodicals."
"human gap periodicals." » "human soap periodicals.", "human hop periodicals.", "human upp periodicals.", "human gait periodicals.", "human gaze periodicals.", "human a periodicals."

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: (("human bees periodicals.") or ((("human gas periodicals.") OR ("human gap periodicals."))))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("human bees periodicals.") OR ((("human gas periodicals.") OR ("human gap periodicals.")))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"human bees periodicals.\") or (((\"human gas periodicals.\") OR (\"human gap periodicals.\"))))".
• Removing quotes may allow a broader search: (( human bees periodicals. ) or ((( human gas periodicals. ) OR ( human gap periodicals. )))).
• Adding a wildcard symbol may retrieve word variants: (("human bees periodicals.") or ((("human gas periodicals.") OR ("human gap periodicals."))))*.