Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
sach kem » hanh kem
hieu van » hieu va, thien van, lieu va
hau truc » cau truc, hang truc, hoc truc
hanh dai » hanh tai, hanh dao, vanh dai
nang xa » nang x, lang xa, nang ma
van hau » van ha, van hai, van dau
truc va » thuc va, thuc vat, trung va
va hanh » van hanh, va thanh, va danh
cua tre » cua te, cuu tre, dua tren
sac ky » cac ky, sai ky

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