Perhaps you should try some spelling variations:
dau tren » dau tien, dat tren, dau tieng
te sach » toc sach
sach ky » sac ky, sach y, sach ty
cao hoi » cau hoi, co hoi, cao hoc
hieu va » lieu va, hieu qua
cam tuc » cam xuc, cam tu, nam thuc
va cam » va cham, va cac, va cao
va dan » ca dan, va dau, va dap
va dao » ca dao
ca dau » ca dao, ca dan, 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 hoi. hieu va cam tuc ((va dan) OR (va dao)) ca dau tren~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ky nang cao hoi. hieu va cam tuc ((va dan) OR (va dao)) ca dau tren".
• Adding a wildcard symbol may retrieve word variants: te sach ky nang cao hoi. hieu va cam tuc ((va dan) OR (va dao)) ca dau tren*.