Perhaps you should try some spelling variations:
thanh trung » thanh tung
thieu cach » hieu cach, thieu cac, thien hach
trung tuan » trung thanh, trung tam, tran tuan
tuan dung » tuan duong, tran dung, tan dung
dung cong » dung trong
hieu cac » hieu luc, hieu va, hieu van
dan toan » van toan, dan than, manh toan

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 cach) OR (hieu cac)) - thanh trung tuan dung cong ((dan toan) or (dan gian)) cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((thieu cach) OR (hieu cac)) - thanh trung tuan dung cong ((dan toan) OR (dan gian)) cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((thieu cach) OR (hieu cac)) - thanh trung tuan dung cong ((dan toan) or (dan gian)) cau".
• Adding a wildcard symbol may retrieve word variants: hoc ((thieu cach) OR (hieu cac)) - thanh trung tuan dung cong ((dan toan) or (dan gian)) cau*.