Perhaps you should try some spelling variations:
hang doi » hang di, hang loi, huong doi
dai hang » dai thang, dai han, dat hang
thuc dai » thuc dan, thuc day, thuc tai
su sach » so sach
doi cua » dai cua, hoi cua
cua tre » cua te, cuu tre, cua triet
vu sach » vu bach, vu khach
le nam » ly nam, he nam, le na
y nang » ky nang, ly nang, v nang
ve nam » he nam, va nam, te nam
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) or (vu sach)) y nang x hoi. hieu ((ve nam) OR (le nam)) thuc dai hang doi 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 nam) OR (le nam)) thuc dai hang doi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su sach) or (vu sach)) y nang x hoi. hieu ((ve nam) OR (le nam)) thuc dai hang doi cua tre".
• Adding a wildcard symbol may retrieve word variants: ((su sach) or (vu sach)) y nang x hoi. hieu ((ve nam) OR (le nam)) thuc dai hang doi cua tre*.