Perhaps you should try some spelling variations:
cao hoc » co hoc, cho hoc, chat hoc
sach ky » sac ky, sach y, sach ty
thuc va » thuc vat, thuc dan, thuc day
cac cau » cac mau, bac cau, ca cau
can cau » van cau, ban cau, ca cau
te sach » toc sach
ve nam » he nam, va nam, te nam
le nam » ly nam, he nam, le na
va dan » ca dan, va dao, va dau

You may be able to get more results by adjusting your search query.

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