Perhaps you should try some spelling variations:
thong tong » thong thong, thong trong, thong cong
nhanh lang » nhanh quang, nhanh thang, nhan dang
hanh mang » nhanh mang, hanh trang, thanh hang
cua thong » cua thuong, cua khong, cua tong
30 trieu » 25 trieu
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.

• The words AND, OR and NOT may confuse the search; try adding quotes: "30 trieu tinh - ((hanh mang) OR (nhanh lang)) cua thong tong tap toan cau~".
• Adding a wildcard symbol may retrieve word variants: 30 trieu tinh - ((hanh mang) OR (nhanh lang)) cua thong tong tap toan cau*.