Perhaps you should try some spelling variations:
hanh tranh » canh tranh, hanh trinh, hanh trang
chieu sang » chieu sach, chieu xanh, nhieu tang
nhung cong » dung cong, thong cong, hang cong
hieu lang » hieu quang, nhieu tang, hieu van
tranh cua » doanh cua, manh cua
cua nhung » va nhung
sach toan » sach tranh, hoach toan, sach tham
hach toan » thanh toan, manh toan

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

• Performing a fuzzy search may retrieve terms with similar spellings: ho ((chieu sang) or (hieu lang)) - hanh tranh cua nhung cong ((sach toan) OR (hach toan)) cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ho ((chieu sang) OR (hieu lang)) - hanh tranh cua nhung cong ((sach toan) OR (hach toan)) cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "ho ((chieu sang) or (hieu lang)) - hanh tranh cua nhung cong ((sach toan) OR (hach toan)) cau".
• Adding a wildcard symbol may retrieve word variants: ho ((chieu sang) or (hieu lang)) - hanh tranh cua nhung cong ((sach toan) OR (hach toan)) cau*.