Perhaps you should try some spelling variations:
bien tinh » bi tinh, yen tinh, diep tinh
cong tuan » cong tan, cong luan, cong thanh
tuan tong » toan tong, thuan trong, toan thong
tong song » tong cong, song song, dong song
thanh cac » hanh cac, thanh bac, thanh ca
song van » hoang van, trong van, duong van
than cua » nhan cua, thai cua, ban cua
so bien » mot bien

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

• Performing a fuzzy search may retrieve terms with similar spellings: so bien tinh - thanh cong tuan tong song van ((than cua) or (thanh cac))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so bien tinh - thanh cong tuan tong song van ((than cua) OR (thanh cac))*.