Perhaps you should try some spelling variations:
"nhat trien khai hoc" » "nhat tien khai hoc", "chat thien khai hoc", "nha triet khai hoc", "nhat trien khi hoc", "nhat trien khai thac", "nhat trien khai hoan"
"phat trien thai hoc" » "phat trien thi hoc", "phat trien thanh hoc", "phat trien thuat hoc", "phat trien dai hoc", "phat trien bai hoc", "phat trien hoi hoc", "phan trien thai hoc", "phap trien thai hoc"
"pham trien nha hoc" » "pham tien nha hoc", "pham tren nha hoc", "pham lien nha hoc", "pham trien he hoc", "pham trien nha thuoc", "pham trien khoa hoc", "pham trien nha nuoc"

Try widening your search to All Fields.

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

• Performing a fuzzy search may retrieve terms with similar spellings: (((("nhat trien khai hoc") or ("phat trien thai hoc"))) or ("pham trien nha hoc"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("nhat trien khai hoc") OR ("phat trien thai hoc"))) OR ("pham trien nha hoc")).
• Removing quotes may allow a broader search: (((( nhat trien khai hoc ) or ( phat trien thai hoc ))) or ( pham trien nha hoc )).
• Adding a wildcard symbol may retrieve word variants: (((("nhat trien khai hoc") or ("phat trien thai hoc"))) or ("pham trien nha hoc"))*.