Perhaps you should try some spelling variations:
van pham » san pham, van phan, van phat
nhan tai » hang tai, van tai, toan tai
tu sach » thu sach, te sach, tu cach
su sach » so sach, vu sach
nang xa » nang x, lang xa, nang ma
va chat » van chat, va phat, cao chat
va nhan » van nhan, ca nhan, va phan
tai va » thai va, mai va, tri va
thiet » thieu

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((tu sach) OR (su sach)) ky nang xa hoi. hieu ((van pham) or (va chat)) duc va nhan tai va thiet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (su sach)) ky nang xa hoi. hieu ((van pham) OR (va chat)) duc va nhan tai va thiet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) OR (su sach)) ky nang xa hoi. hieu ((van pham) or (va chat)) duc va nhan tai va thiet".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) OR (su sach)) ky nang xa hoi. hieu ((van pham) or (va chat)) duc va nhan tai va thiet*.