Perhaps you should try some spelling variations:
thiet tach » chiet tach, thien hach
thuat tach » thuat sach, thuat mach, thuat tac
trung tuan » trung thanh, trung tam, tran tuan
nhung cong » dung cong, thong cong, hang cong
cong quang » luong quang, thong quang, duong quang
quang toan » quang tuan, quang tran, quang doan
trang cua » tranh cua, tang cua, trung cua
toan cau » 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) OR (thuat tach)) - hanh ((trang cua) or (trung tuan)) nhung cong quang toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((thiet tach) OR (thuat tach)) - hanh ((trang cua) OR (trung tuan)) nhung cong quang toan cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((thiet tach) OR (thuat tach)) - hanh ((trang cua) or (trung tuan)) nhung cong quang toan cau".
• Adding a wildcard symbol may retrieve word variants: hoc ((thiet tach) OR (thuat tach)) - hanh ((trang cua) or (trung tuan)) nhung cong quang toan cau*.