Perhaps you should try some spelling variations:
cau treo » cau theo, cau tren, cau triet
va doanh » van doanh, vay doanh, va danh
sang mai » sang ma, sang tai, lang mai
cuu tre » cua tre, cau tren
ve giao » te giao, viet giao, van giao
hieu ve » hieu va, hieu van
mai hoi » mai khoi, dai hoi, lai hoi
ky sang » ky nang, ky dang, ky tang
sac ky » cac ky, sai ky
va dao » ca dao
tu sac » tu sach, tu cac, tu san

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sac ky sang mai hoi. hieu ve giao duc ((va doanh) or (va dao)) lai ((cuu tre) or (cau treo))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sac ky sang mai hoi. hieu ve giao duc ((va doanh) OR (va dao)) lai ((cuu tre) OR (cau treo)).
• Adding a wildcard symbol may retrieve word variants: tu sac ky sang mai hoi. hieu ve giao duc ((va doanh) or (va dao)) lai ((cuu tre) or (cau treo))*.