Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
thuc dan » thuc hanh, hoc dan, thuc vat
cam thuc » am thuc, nam thuc, cam thu
danh di » danh du, xanh di, danh dien
sach ty » sach y, sach thu, xach tay
van cam » van nam, van lam, van cau
nang xa » nang x, lang xa, nang ma
sach tu » sach thu, cach tu, sach uu
cuu tre » cua tre, cau tren, cau treo

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 ty) OR (sach tu)) nang xa hoi. hieu van cam thuc dan ((hanh vi) or (danh di)) cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sach ty) OR (sach tu)) nang xa hoi. hieu van cam thuc dan ((hanh vi) OR (danh di)) cuu tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su ((sach ty) OR (sach tu)) nang xa hoi. hieu van cam thuc dan ((hanh vi) or (danh di)) cuu tre*".