Perhaps you should try some spelling variations:
sach thue » sach thu, sach thieu, sach tham
va triet » va thiet, va trien, ve triet
cham duc » pham duc, cham soc, pham duy
hanh dai » hanh tai, hanh dao, vanh dai
tan hanh » tan thanh, tang hanh, toan hanh
hieu van » thien van, lieu va, hieu ve
sach tu » sach thu, cach tu, sach ty
hieu va » lieu va, hieu qua
nang xa » nang x, lang xa, nang ma
dai va » mai va

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 tu) or (sach thue)) nang xa hoi. ((hieu van) OR (hieu va)) cham duc tan hanh dai va triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach tu) OR (sach thue)) nang xa hoi. ((hieu van) OR (hieu va)) cham duc tan hanh dai va triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sach tu) or (sach thue)) nang xa hoi. ((hieu van) OR (hieu va)) cham duc tan hanh dai va triet".
• Adding a wildcard symbol may retrieve word variants: tu ((sach tu) or (sach thue)) nang xa hoi. ((hieu van) OR (hieu va)) cham duc tan hanh dai va triet*.