Perhaps you should try some spelling variations:
cau tren » cu tren, dau tren, cau treo
ca tren » cu tren, la tren, co tren
nang ma » tang ma, sang ma, mang may
danh vi » hanh vi, dinh vi, danh di
va danh » va dinh, va dan, va hanh
hai xuc » hai cuc, hai xu, chat xuc
hieu va » lieu va, hieu qua
va hai » van hai, va chai, va khai
xuc va » duc va, tuc va, luc va
su cao » cu cao, vu cao, su co

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

• Performing a fuzzy search may retrieve terms with similar spellings: su cao ky ((nang ma) or (nang cao)) hoi. hieu va hai xuc va danh vi ((cau tren) OR (ca tren))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su cao ky ((nang ma) OR (nang cao)) hoi. hieu va hai xuc va danh vi ((cau tren) OR (ca tren)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "su cao ky ((nang ma) or (nang cao)) hoi. hieu va hai xuc va danh vi ((cau tren) OR (ca tren))".
• Adding a wildcard symbol may retrieve word variants: su cao ky ((nang ma) or (nang cao)) hoi. hieu va hai xuc va danh vi ((cau tren) OR (ca tren))*.