Perhaps you should try some spelling variations:
thien hach » thien thanh, hien hanh
hieu thien » hieu hien, chieu chien, dieu khien
hach qua » bach qua, hanh qua, sach quan
nhanh ha » thanh hoa, thanh hai, khanh hoa
thanh ha » thanh hoa, thanh hai, thanh phan
cua tre » cua te, cuu tre, cua triet
ky tang » ky nang, ky dang, kho tang
ky lang » ky nang, ky dang, tay lang
qua va » quan va, qua van, vua va
tu ban » thu ban, te ban

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu ban ((ky lang) OR (ky tang)) xa hoi. hieu thien hach qua va ((thanh ha) or (nhanh ha)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ban ((ky lang) OR (ky tang)) xa hoi. hieu thien hach qua va ((thanh ha) OR (nhanh ha)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ban ((ky lang) OR (ky tang)) xa hoi. hieu thien hach qua va ((thanh ha) or (nhanh ha)) cua tre".
• Adding a wildcard symbol may retrieve word variants: tu ban ((ky lang) OR (ky tang)) xa hoi. hieu thien hach qua va ((thanh ha) or (nhanh ha)) cua tre*.