Perhaps you should try some spelling variations:
su triet » su viet, su tien, ve triet
hanh hai » thanh hai, nhanh hai, hang hai
ban hanh » ban hang
duc ban » duc tan, duc van, dua ban
cua tre » cua te, cuu tre, cua triet
ve pham » vi pham, v pham, ve phan
hieu ve » hieu va, hieu van
ky dang » ky nang, ky danh
ky tang » ky nang, kho tang, ky trong
su dai » sau dai, si dai, su tai

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

• Performing a fuzzy search may retrieve terms with similar spellings: su dai ((ky tang) OR (ky dang)) xa hoi. hieu ve pham duc ban hanh hai ((cua tre) or (su triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su dai ((ky tang) OR (ky dang)) xa hoi. hieu ve pham duc ban hanh hai ((cua tre) OR (su triet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "su dai ((ky tang) OR (ky dang)) xa hoi. hieu ve pham duc ban hanh hai ((cua tre) or (su triet))".
• Adding a wildcard symbol may retrieve word variants: su dai ((ky tang) OR (ky dang)) xa hoi. hieu ve pham duc ban hanh hai ((cua tre) or (su triet))*.