Perhaps you should try some spelling variations:
thuong tong » thuong trong, thuong dong, tuong tong
chieu xanh » chieu sach, chieu tinh, hieu manh
chieu sang » chieu sach, hieu lang, nhieu tang
trang cua » tranh cua, tang cua, thang cua
trung cua » truong cua, trung tuan, trung cap
tong tap » tuong tac, trong tan, cong tac
tap toan » tap doan, tap quan, bai toan
toan cau » toan cao, toan ban, toan tap

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

• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((chieu xanh) OR (chieu sang)) - hanh ((trang cua) OR (trung cua)) thuong tong tap toan cau~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((chieu xanh) or (chieu sang)) - hanh ((trang cua) OR (trung cua)) thuong tong tap toan cau~".
• Adding a wildcard symbol may retrieve word variants: hoc ((chieu xanh) or (chieu sang)) - hanh ((trang cua) OR (trung cua)) thuong tong tap toan cau*.