Perhaps you should try some spelling variations:
cua viet » ca viet, hoa viet, cua vat
hieu van » hieu va, thien van, lieu va
hanh lai » hanh lam, hanh tai, thanh lap
thuc dan » thuc hanh, hoc dan, thuc vat
nang xa » nang x, lang xa, nang ma
van dau » van dao, phan dau
truc va » thuc va, thuc vat, trung va
sach ty » sach tu, sach thu, xach tay
lai cua » dai cua, hai cua, lai chau

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 y) or (sach ty)) nang xa hoi. hieu van dau ((truc va) or (thuc dan)) hanh lai cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach y) OR (sach ty)) nang xa hoi. hieu van dau ((truc va) OR (thuc dan)) hanh lai cua viet.
• Adding a wildcard symbol may retrieve word variants: tu ((sach y) or (sach ty)) nang xa hoi. hieu van dau ((truc va) or (thuc dan)) hanh lai cua viet*.