Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
sang mai » sang ma, sang tai, lang mai
mai khoi » mai khoa, tai khoa, cac khoi
cam quoc » cac quoc, cao quoc, nam quoc
quoc ban » quoc bao, quoc lan, quoc quan
ban banh » ban hanh, ban anh, ban danh
banh dai » benh dai, ban dai, vanh dai
ky sang » ky nang, ky dang, ky tang
hieu va » hieu qua
tu sac » tu sach, tu san, tu bac

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) OR (tu cac)) ky sang mai khoi. ((lieu va) or (hieu va)) cam quoc ban banh dai cua triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sac) OR (tu cac)) ky sang mai khoi. ((lieu va) OR (hieu va)) cam quoc ban banh dai cua triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sac) OR (tu cac)) ky sang mai khoi. ((lieu va) or (hieu va)) cam quoc ban banh dai cua triet".
• Adding a wildcard symbol may retrieve word variants: ((tu sac) OR (tu cac)) ky sang mai khoi. ((lieu va) or (hieu va)) cam quoc ban banh dai cua triet*.