Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
tu sach » thu sach, su sach, te sach
cau hoa » cau hoi
hoi cua » hoi chuc
doi cua » dai cua
hoa ban » hoa dan, hoa van, hoa han
sach ty » sach y, sach tu, sach thu
hieu ve » hieu va, hieu van
nang xa » nang x, lang xa, nang ma
ty nang » ky nang, ty xang, ty hang

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 ty nang xa hoi. ((hieu ve) or (lieu va)) cau hoa ban thanh ((doi cua) OR (hoi cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty nang xa hoi. ((hieu ve) OR (lieu va)) cau hoa ban thanh ((doi cua) OR (hoi cua)) tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ty nang xa hoi. ((hieu ve) or (lieu va)) cau hoa ban thanh ((doi cua) OR (hoi cua)) tre".
• Adding a wildcard symbol may retrieve word variants: tu sach ty nang xa hoi. ((hieu ve) or (lieu va)) cau hoa ban thanh ((doi cua) OR (hoi cua)) tre*.