Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
cam thuc » am thuc, nam thuc, cam thu
su sach » so sach, vu sach
sach tu » sach thu, cach tu, sach ty
tu nang » tru nang, tu nong, tu nano
van cam » van nam, van lam, van cau
thuc va » thuc vat, thuc dan, thuc day
danh va » doanh va, hanh va, anh va
danh di » danh du, xanh di, danh dien
cua tre » cua te, cuu tre, cua triet
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: su sach tu nang x hoi. hieu van cam thuc va ((danh va) or (danh di)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach tu nang x hoi. hieu van cam thuc va ((danh va) OR (danh di)) cua tre*.