Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
cham duc » pham duc, cham soc, pham duy
va triet » va trien, ve triet, cua triet
sach thu » sach thue, sach thieu, sach tham
hanh dai » hanh tai, hanh dao, vanh dai
tan hanh » tan thanh, tang hanh, toan hanh
van cham » van chat, van tham, va cham
sach tu » cach tu, sach ty, sach uu
x hoi » xa hoi, o hoi, x ho
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 tu) or (sach thu)) nang x hoi. hieu van cham duc tan hanh dai ((va triet) OR (va thiet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach tu) OR (sach thu)) nang x hoi. hieu van cham duc tan hanh dai ((va triet) OR (va thiet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sach tu) or (sach thu)) nang x hoi. hieu van cham duc tan hanh dai ((va triet) OR (va thiet))".
• Adding a wildcard symbol may retrieve word variants: tu ((sach tu) or (sach thu)) nang x hoi. hieu van cham duc tan hanh dai ((va triet) OR (va thiet))*.