Perhaps you should try some spelling variations:
quoc ban » quoc bao, quoc lan, quoc quan
tu sach » thu sach, su sach, tu cach
hang vi » hang va, hanh vi, hang di
xuc ban » duc ban, cuc ban, xuat ban
cua tre » cua te, cuu tre, cua triet
hieu va » lieu va, hieu qua
lang xa » lang ha, dang xay, lang van
ky lang » ky nang, ky dang, ky tang
te sach » toc sach
vi cua » vai cua, di cua
va cao » va cac, va co, va dao

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

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