Perhaps you should try some spelling variations:
dong thanh » truong thanh
hoc chieu » ho chieu, hoc hien, hoc dieu
hoc thieu » toc thieu, hoc hien
toan thuc » toan hoc, dan thuc, nhan thuc
thuc hung » thuc chung, thuc nhung, thuc dung
cong than » cong thanh, cong thang, cong tan
phan lap » phan dau

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((hoc chieu) OR (hoc thieu)) xanh - tinh toan thuc hung ((cong than) or (dong thanh)) phan lap~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((hoc chieu) OR (hoc thieu)) xanh - tinh toan thuc hung ((cong than) OR (dong thanh)) phan lap.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((hoc chieu) OR (hoc thieu)) xanh - tinh toan thuc hung ((cong than) or (dong thanh)) phan lap".
• Adding a wildcard symbol may retrieve word variants: ((hoc chieu) OR (hoc thieu)) xanh - tinh toan thuc hung ((cong than) or (dong thanh)) phan lap*.