Perhaps you should try some spelling variations:
thiet tach » chiet tach, thien hach, thuat tach
hoc thiet » hoc thieu, hoc thuyet, hoc hien
dung cong » dung trong
tram van » tran van, trang van, tranh van
cong dan » cong san, cong tan, huong dan
dan than » dan chan, ban than, van than
than cau » toan cau, phan cau, than cap
tam van » nam van, dam van, tom van

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

• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc thiet tach - hanh ((tram van) OR (tam van)) dung cong dan than cau~".
• Adding a wildcard symbol may retrieve word variants: hoc thiet tach - hanh ((tram van) OR (tam van)) dung cong dan than cau*.