Perhaps you should try some spelling variations:
thiet tach » chiet tach, thien hach, thuat tach
canh trinh » canh tranh, hanh trinh, canh tinh
chong cong » thong cong, cuong cong, phong cong
hoc thiet » hoc thieu, hoc thuyet, hoc hien
trinh cac » trinh cau, trinh chat, trinh chao
cong cong » cong dong, trong cong, dung cong
dan toan » van toan, dan than, manh toan
toan ban » van 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 thiet tach - canh trinh cac ((chong cong) or (cong cong)) dan toan ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc thiet tach - canh trinh cac ((chong cong) OR (cong cong)) dan toan ban*.