Perhaps you should try some spelling variations:
cham thuc » nham thuc, pham thuc, tham thuc
can cau » van cau, ban cau, ca cau
cac cau » cac mau, bac cau, ca cau
thuc va » thuc vat, thuc dan, thuc day
tu sach » thu sach, su sach, te sach
hieu ve » hieu va, hieu van
cho hoc » co hoc, khoa hoc
ve cham » va cham, ve chat, vu cham
y nang » ky nang, ly nang, may nang
va dan » ca dan, va dao, va dau
v nang » va nang, vu nang, van nang

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 ((y nang) or (v nang)) cho hoc. hieu ve cham thuc va dan ((cac cau) or (can cau)) tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((y nang) OR (v nang)) cho hoc. hieu ve cham thuc va dan ((cac cau) OR (can cau)) tren.
• Adding a wildcard symbol may retrieve word variants: tu sach ((y nang) or (v nang)) cho hoc. hieu ve cham thuc va dan ((cac cau) or (can cau)) tren*.