Perhaps you should try some spelling variations:
thu sach » thuat sach, thuoc sach, thu hoach
tru nang » tra nang, tri nang, truc nano
va triet » va trien, ve triet, cua triet
hieu van » hieu va, thien van, lieu va
dang hai » dang khai, hang hai, dung hai
tu sach » su sach, te sach, tu cach
va dang » van dang, va nang, va lang
van hac » van hoc, van ha, van hai
hac xuc » chat xuc
nang xa » nang x, lang xa, nang ma
xuc va » duc va, tuc va, luc 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 van hac xuc va dang hai ((va triet) OR (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 van hac xuc va dang hai ((va triet) OR (va thiet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (thu sach)) tru nang xa hoi. hieu van hac xuc va dang hai ((va triet) OR (va thiet))".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (thu sach)) tru nang xa hoi. hieu van hac xuc va dang hai ((va triet) OR (va thiet))*.