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
danh hai » dang hai, lanh hai, manh hai
tu sach » su sach, te sach, tu cach
va danh » va dinh, va dan, va hanh
qua hac » qua hai, qua cac, qua hoat
hac tuc » thac toc, thai tuc
nang xa » nang x, lang xa, nang ma
tuc va » thuc va, truc va, tuc xa
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 qua hac tuc va danh 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 qua hac tuc va danh 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 qua hac tuc va danh hai ((va triet) OR (va thiet))".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (thu sach)) tru nang xa hoi. hieu qua hac tuc va danh hai ((va triet) OR (va thiet))*.