Perhaps you should try some spelling variations:
hieu quang » thieu quang, hieu quan, hieu qua
thong danh » thong dan, thong lanh, trong danh
danh toan » manh toan, anh toan, dan toan
trung va » truong va, trang va, trung ha
tran van » luan van
toan cau » toan cao, toan ban, toan tap
ho hieu » ho chieu, hoi hieu, nho hieu

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

• Performing a fuzzy search may retrieve terms with similar spellings: ho hieu quang - hanh ((trung va) or (tran van)) thong thong danh toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ho hieu quang - hanh ((trung va) OR (tran van)) thong thong danh toan cau.
• Adding a wildcard symbol may retrieve word variants: ho hieu quang - hanh ((trung va) or (tran van)) thong thong danh toan cau*.