Perhaps you should try some spelling variations:
"human genes periodicals." » "human genomes periodicals.", "human bees periodicals.", "human games periodicals.", "human gene periodicals.", "human genetics periodicals.", "human genetic periodicals."
"human gases periodicals." » "human games periodicals.", "human leases periodicals.", "human gas periodicals.", "human cases periodicals.", "human causes periodicals.", "human gamers periodicals."
"human ages periodicals." » "human agents periodicals.", "human bees periodicals.", "human changes periodicals.", "human age periodicals.", "human images 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 genes periodicals.") or ("human gases periodicals."))) or ("human ages periodicals."))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("human genes periodicals.") OR ("human gases periodicals."))) OR ("human ages periodicals."))*.
• Removing quotes may allow a broader search: (((( human genes periodicals. ) or ( human gases periodicals. ))) or ( human ages periodicals. ))*.