Perhaps you should try some spelling variations:
hien khanh » hien hanh, dien khanh, thien thanh
hien nhanh » hien hanh, thien thanh, tien thanh
tong thong » thong thong, dong thong, cong thong
hanh han » hanh nhan, hanh phan, hanh san
cua tong » cua cong, cua dong, cua nong
tai toan » tap toan, tai tuan, tam toan
bai toan » bai tap
han cua » hang cua, nhan cua, than cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc ((hien khanh) or (hien nhanh)) - hanh han cua tong thong ((tai toan) OR (bai toan)) ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((hien khanh) OR (hien nhanh)) - hanh han cua tong thong ((tai toan) OR (bai toan)) ban.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((hien khanh) or (hien nhanh)) - hanh han cua tong thong ((tai toan) OR (bai toan)) ban".
• Adding a wildcard symbol may retrieve word variants: hoc ((hien khanh) or (hien nhanh)) - hanh han cua tong thong ((tai toan) OR (bai toan)) ban*.