Perhaps you should try some spelling variations:
hoc thieu » toc thieu, hoc hien
tran nang » tra nang, tran quang, tran hoang
tran dang » tran quang, tran hoang, tranh hang
tong cong » trong cong, cong cong, dung cong
doc hieu » toc thieu, hoc hien
cong dan » cong san, cong tan, huong dan
dan toan » van toan, dan than, manh toan
toan tap » toan ban

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((hoc thieu) or (doc hieu)) xanh - thanh ((tran nang) OR (tran dang)) tong cong dan toan tap~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((hoc thieu) OR (doc hieu)) xanh - thanh ((tran nang) OR (tran dang)) tong cong dan toan tap.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((hoc thieu) or (doc hieu)) xanh - thanh ((tran nang) OR (tran dang)) tong cong dan toan tap".
• Adding a wildcard symbol may retrieve word variants: ((hoc thieu) or (doc hieu)) xanh - thanh ((tran nang) OR (tran dang)) tong cong dan toan tap*.