Perhaps you should try some spelling variations:
ban hanh » ban hang
toc sach » hoc sach, doc sach, thuoc sach
cac quoc » cac nuoc, cac cuoc, cao quoc
cam quoc » cao quoc, nam quoc, han quoc
cua tre » cua te, cuu tre, cua triet
lang xa » lang ha, dang xay, lang van
ky lang » ky nang, ky dang, ky tang
vi cua » vai cua, di cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((te sach) or (toc sach)) ky lang xa hoi. lieu va ((cam quoc) OR (cac quoc)) ban hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (toc sach)) ky lang xa hoi. lieu va ((cam quoc) OR (cac quoc)) ban hanh vi cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) or (toc sach)) ky lang xa hoi. lieu va ((cam quoc) OR (cac quoc)) ban hanh vi cua tre*".