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

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