Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
cam thuc » am thuc, nam thuc, cam thu
hanh noi » ha noi, hanh vi, nang noi
tu sach » thu sach, su sach, te sach
sach ty » sach y, sach tu, sach thu
nang xa » nang x, nang ma, mang xa
lang xa » lang ha, dang xay, lang van
van cam » van nam, van lam, van cau
thuc va » thuc vat, thuc dan, thuc day
va hanh » van hanh, va thanh, va danh
su viet » so viet
noi su » noi suc, noi so, oi su

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 ty ((nang xa) or (lang xa)) hoi. hieu van cam thuc va hanh noi su viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty ((nang xa) OR (lang xa)) hoi. hieu van cam thuc va hanh noi su viet*.