Perhaps you should try some spelling variations:
tran thanh » ban thanh, van thanh, quan thanh
hien xanh » hien hanh, hien nhanh, chieu xanh
huong cua » dung cua
thong tai » truong tai, thong tin, hang tai
hang cua » mang cua, hang ca, thong cua
tai toan » bai toan, tap toan, tai tuan
toan tap » toan ban

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 ((hien xanh) OR (tran thanh)) - hanh ((hang cua) OR (huong cua)) thong thong tai toan tap~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((hien xanh) or (tran thanh)) - hanh ((hang cua) OR (huong cua)) thong thong tai toan tap~".
• Adding a wildcard symbol may retrieve word variants: hoc ((hien xanh) or (tran thanh)) - hanh ((hang cua) OR (huong cua)) thong thong tai toan tap*.