Perhaps you should try some spelling variations:
dat hang » dat khanh, dat quang, tat thang
dai hang » dai thang, dai han, dai dang
su sach » so sach
hoi cua » hoi chuc
cua tre » cua te, cuu tre, cua triet
vu sach » vu bach, vu khach
hieu ve » hieu va, hieu van
y nang » ky nang, ly nang, v nang
x hoi » xa hoi, o hoi, x ho
ve am » va am

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) or (vu sach)) y nang x hoi. hieu ve am thuc ((dai hang) or (dat hang)) hoi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (vu sach)) y nang x hoi. hieu ve am thuc ((dai hang) OR (dat hang)) hoi cua tre.
• Adding a wildcard symbol may retrieve word variants: ((su sach) or (vu sach)) y nang x hoi. hieu ve am thuc ((dai hang) or (dat hang)) hoi cua tre*.