Perhaps you should try some spelling variations:
cau tren » cu tren, ca tren, cau treo
dau tren » dau tien, dat tren, dau tieng
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
hieu va » lieu va, hieu qua
cau luc » cau truc, cau phuc
va cau » van cau, va cac, va cao
va dan » ca dan, va dao, va dap
va dau » va dao

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

• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang x ho. hieu va cau luc ((va dan) OR (va dau)) vi ((cau tren) OR (dau tren))~.
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang x ho. hieu va cau luc ((va dan) or (va dau)) vi ((cau tren) or (dau tren))*.