Perhaps you should try some spelling variations:
thiet tach » chiet tach, thien hach, thuat tach
hanh thang » nhanh thang, thanh thang, hanh trang
nhung cong » dung cong, thong cong, nhung don
hoc thiet » hoc thieu, hoc thuyet, hoc hien
hang cong » dang cong, hang nong, thanh cong
bang cong » dang cong, bang song, dung cong
thang va » hang va, trang va, thong va
tan toan » tan tran, tap toan, van toan
toan cao » toan ban, toan tap

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 - hanh thang va ((nhung cong) or (((hang cong) or (bang cong)))) tan toan cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc thiet tach - hanh thang va ((nhung cong) OR (((hang cong) OR (bang cong)))) tan toan cao.
• Adding a wildcard symbol may retrieve word variants: hoc thiet tach - hanh thang va ((nhung cong) or (((hang cong) or (bang cong)))) tan toan cao*.