Perhaps you should try some spelling variations:
cham thuc » nham thuc, pham thuc, tham thuc
dua tren » dung tren
sach tu » sach thu, cach tu, sach ty
dau lai » dao lai, dat lai, dau hai
thuc va » thuc vat, thuc dan, thuc day
su sach » so sach, vu sach
ve cham » va cham, ve chat, vu cham
hieu ve » hieu va, hieu van
hang ca » hang va, nang cao, hang tai
tu hang » thu hang, tu hanh, tu hung
cuu tre » cua tre, cau tren, cau treo
va dau » va dao
ca hoi » cau hoi, cua hoi, xa hoi

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 hang ca hoi. hieu ve cham thuc va dau lai ((dua tren) or (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach tu hang ca hoi. hieu ve cham thuc va dau lai ((dua tren) OR (cuu tre))*.