Perhaps you should try some spelling variations:
sach tru » sach truc, sach thu, sach tu
tru nang » tra nang, tri nang, truc nano
va triet » va trien, ve triet, cua triet
tu sach » thu sach, su sach, te sach
va lang » va nang, hoa lang
va lanh » va danh, va hanh, va anh
hac xuc » chat xuc
hieu va » lieu va, hieu qua
nang xa » nang x, lang xa, nang ma
va hac » van hac, va khac, va cac
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 tru nang xa hoi. hieu va hac xuc ((va lanh) or (va lang)) hai ((va triet) OR (va thiet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach tru nang xa hoi. hieu va hac xuc ((va lanh) OR (va lang)) hai ((va triet) OR (va thiet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach tru nang xa hoi. hieu va hac xuc ((va lanh) or (va lang)) hai ((va triet) OR (va thiet))".
• Adding a wildcard symbol may retrieve word variants: tu sach tru nang xa hoi. hieu va hac xuc ((va lanh) or (va lang)) hai ((va triet) OR (va thiet))*.