Perhaps you should try some spelling variations:
vien dai » hien dai
hang tai » dung tai
vien cao » vien cac, vien da, vien va
duc ban » duc tan, duc van, dua ban
su sach » so sach, vu sach
cua tre » cua te, cuu tre, cua triet
y nang » ky nang, ly nang, v nang
x hoi » xa hoi, o hoi, x ho

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach y nang x hoi. hieu ((vien cao) OR (vien dai)) duc ban ((hang tai) or (hang va)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach y nang x hoi. hieu ((vien cao) OR (vien dai)) duc ban ((hang tai) OR (hang va)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach y nang x hoi. hieu ((vien cao) OR (vien dai)) duc ban ((hang tai) or (hang va)) cua tre".
• Adding a wildcard symbol may retrieve word variants: su sach y nang x hoi. hieu ((vien cao) OR (vien dai)) duc ban ((hang tai) or (hang va)) cua tre*.