Perhaps you should try some spelling variations:
cong ngang » cong nhan, cong quang, cong lang
hieu lang » chieu sang, hieu quang, nhieu tang
va phuong » va thuong, cac phuong
doi hieu » doi chieu, doc hieu, doi hien
hanh han » hanh nhan, hanh phan, hanh san
va thong » va thuong, he thong, va cong
tuan cau » toan cau, tuan cu, thuan cam
quan cau » quang cao, toan cau, quan ha

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