Perhaps you should try some spelling variations:
thien van » thi van
hanh dai » hanh tai, hanh dao, vanh dai
cua viet » ca viet, hoa viet, cua vat
so sach » so sanh, bo sach, co sach
sach lo » sach dao, sach doi, sach hoi
lo nang » ho nang, ly nang, loai nang
van cam » van nam, van lam, van cau
truc va » thuc va, thuc vat, trung va
x hoi » xa hoi, o hoi, x ho

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: so sach lo nang x hoi. thien van cam ((duc va) or (truc va)) hanh dai cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach lo nang x hoi. thien van cam ((duc va) OR (truc va)) hanh dai cua viet.
• Adding a wildcard symbol may retrieve word variants: so sach lo nang x hoi. thien van cam ((duc va) or (truc va)) hanh dai cua viet*.