Perhaps you should try some spelling variations:
ban thanh » ban hang
ban hanh » ban hang
tu sach » thu sach, su sach, te sach
cao hoc » co hoc, cho hoc, chat hoc
hieu ve » hieu va, hieu van
cac cuc » cac cuoc, cac cua, cac nuoc
buu tre » cuu tre
ve cac » va cac, vien cac

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 (thu hoach)) ky nang cao hoc. hieu ve cac cuc ((ban thanh) OR (ban hanh)) tai buu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thu hoach)) ky nang cao hoc. hieu ve cac cuc ((ban thanh) OR (ban hanh)) tai buu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (thu hoach)) ky nang cao hoc. hieu ve cac cuc ((ban thanh) OR (ban hanh)) tai buu tre".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (thu hoach)) ky nang cao hoc. hieu ve cac cuc ((ban thanh) OR (ban hanh)) tai buu tre*.