Perhaps you should try some spelling variations:
khai duc » khai dich, khai luoc, pham duc
cau tren » cu tren, dau tren, ca tren
nang ma » tang ma, nang cao, mang may
sang ma » tang ma, sang tao, mang may
hieu va » lieu va, hieu qua
va khai » van khai, va khao, va kha
va danh » va dinh, va dan, va hanh
danh vi » hanh vi, dinh vi, danh di
su cac » tu cac, su cao, su can
vi cau » va cau, ve cau, di cau

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

• Performing a fuzzy search may retrieve terms with similar spellings: su cac ky ((nang ma) OR (sang ma)) hoi. hieu va khai duc va danh vi cau tren~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su cac ky ((nang ma) OR (sang ma)) hoi. hieu va khai duc va danh vi cau tren".
• Adding a wildcard symbol may retrieve word variants: su cac ky ((nang ma) OR (sang ma)) hoi. hieu va khai duc va danh vi cau tren*.