Perhaps you should try some spelling variations:
cham thuc » nham thuc, pham thuc, tham thuc
thu sach » thuat sach, thuoc sach, thu hoach
nang cho » nang chon, ngang cho, nang cao
can cau » van cau, ban cau, cac cau
thuc va » thuc vat, thuc dan, thuc day
tu sach » su sach, te sach, tu cach
hieu ve » hieu va, hieu van
cho hoc » co hoc, khoa hoc
ve cham » va cham, ve chat, vu cham
va dan » ca dan, va dao, va dau
ca cau » cua cau, cac cau, ca cac

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) OR (thu sach)) ky nang cho hoc. hieu ve cham thuc va dan ((ca cau) or (can cau)) tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thu sach)) ky nang cho hoc. hieu ve cham thuc va dan ((ca cau) OR (can cau)) tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) OR (thu sach)) ky nang cho hoc. hieu ve cham thuc va dan ((ca cau) or (can cau)) tren".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) OR (thu sach)) ky nang cho hoc. hieu ve cham thuc va dan ((ca cau) or (can cau)) tren*.