Perhaps you should try some spelling variations:
qua cham » qua hai, qua cac, va cham
su sach » so sach, vu sach
duc van » duc va, duc tan, duc manh
dua ban » dia ban, cua ban, qua ban
cua tre » cua te, cuu tre, cua triet
y nang » ky nang, ly nang, v nang
anh do » anh doc, anh d, anh co
do cua » doi cua, co cua, de cua
x hoi » o hoi, x ho, 5 hoi

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) or (xa hoi)). hieu qua cham ((duc van) or (dua ban)) anh do cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach y nang ((x hoi) OR (xa hoi)). hieu qua cham ((duc van) OR (dua ban)) anh do cua tre.
• Adding a wildcard symbol may retrieve word variants: su sach y nang ((x hoi) or (xa hoi)). hieu qua cham ((duc van) or (dua ban)) anh do cua tre*.