Perhaps you should try some spelling variations:
thu sach » thuat sach, thuoc sach, thu hoach
tru nang » tra nang, tri nang, truc nano
dang hai » dang khai, hang hai, dung hai
tu sach » su sach, te sach, tu cach
nang xa » nang x, lang xa, nang ma
hieu va » lieu va, hieu qua
hac xuc » chat xuc
va dang » van dang, va nang, va lang
va hac » van hac, va khac, va cac
xuc va » duc va, tuc va, luc va
hai va » hai van, thai va, hoi 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 (thu sach)) tru nang xa hoi. hieu va hac xuc va dang hai va thiet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thu sach)) tru nang xa hoi. hieu va hac xuc va dang hai va thiet.
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (thu sach)) tru nang xa hoi. hieu va hac xuc va dang hai va thiet*.