Perhaps you should try some spelling variations:
hoc thiet » hoc thieu, hoc thuyet, hoc hien
thiet anh » thien anh, thuyet anh, thien danh
tranh cua » doanh cua, manh cua
thanh cao » thanh cac, thanh thao, thanh cham
cong ban » cong bang, cong tan, cong dan
cong san » cong tac
thanh ca » thanh cha, thanh cac, thanh ha

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc thiet anh - canh tranh cua ban ((cong ban) OR (cong san)) ((thanh cao) or (thanh ca))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc thiet anh - canh tranh cua ban ((cong ban) OR (cong san)) ((thanh cao) OR (thanh ca)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc thiet anh - canh tranh cua ban ((cong ban) OR (cong san)) ((thanh cao) or (thanh ca))".
• Adding a wildcard symbol may retrieve word variants: hoc thiet anh - canh tranh cua ban ((cong ban) OR (cong san)) ((thanh cao) or (thanh ca))*.