Perhaps you should try some spelling variations:
ngang tuan » quang tuan, hoang tuan, trang tuan
nganh toan » nganh thanh, thanh toan, manh toan
hieu lang » chieu sang, hieu quang, nhieu tang
hanh hang » thanh hang, hang hang, hanh han
va phuong » va thuong, cac phuong
doi hieu » doi chieu, doc hieu, doi hien
va thong » va thuong, he thong, va cong

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

• Performing a fuzzy search may retrieve terms with similar spellings: doi hieu lang - hanh hang ((va thong) or (va phuong)) cong ((ngang tuan) OR (nganh toan)) cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doi hieu lang - hanh hang ((va thong) OR (va phuong)) cong ((ngang tuan) OR (nganh toan)) cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doi hieu lang - hanh hang ((va thong) or (va phuong)) cong ((ngang tuan) OR (nganh toan)) cau".
• Adding a wildcard symbol may retrieve word variants: doi hieu lang - hanh hang ((va thong) or (va phuong)) cong ((ngang tuan) OR (nganh toan)) cau*.