Perhaps you should try some spelling variations:
tham hoc » thai hoc, tham hoa, than hoc
ban hang » ngan hang
thai cua » than cua, tai cuc, tri cua
su sach » so sach, vu sach
lang xa » lang ha, dang xay, lang van
hieu va » lieu va
hoc ban » hoc bang, hoc dan, hoc bai
hai cua » dai cua, hoi cua, lai cua

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 _ lang xa hoi. ((hieu va) OR (hieu qua)) tham hoc ban hang ((hai cua) or (thai cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach _ lang xa hoi. ((hieu va) OR (hieu qua)) tham hoc ban hang ((hai cua) OR (thai cua)) tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach _ lang xa hoi. ((hieu va) OR (hieu qua)) tham hoc ban hang ((hai cua) or (thai cua)) tre".
• Adding a wildcard symbol may retrieve word variants: su sach _ lang xa hoi. ((hieu va) OR (hieu qua)) tham hoc ban hang ((hai cua) or (thai cua)) tre*.