Perhaps you should try some spelling variations:
trinh toan » tinh toan, thanh toan, trinh han
hoc thieu » toc thieu, hoc hien
trang van » tran van, trong van, tang van
dung cong » dung trong
theo chu » theo chieu, cho chu, chao chu
trang va » tran van, hang va
toan cao » toan ban, toan tap

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

• If you are trying to use Boolean operators, they must be ALL CAPS: ((hoc thieu) OR (theo chu)) xanh - hanh ((trang van) OR (trang va)) dung cong trinh toan cao~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((hoc thieu) or (theo chu)) xanh - hanh ((trang van) OR (trang va)) dung cong trinh toan cao~".
• Adding a wildcard symbol may retrieve word variants: ((hoc thieu) or (theo chu)) xanh - hanh ((trang van) OR (trang va)) dung cong trinh toan cao*.