Perhaps you should try some spelling variations:
nhung cong » dung cong, thong cong, hang cong
hieu manh » chieu xanh, hieu nganh, dieu hanh
tranh thi » tranh thai, tran thi, trang thai
trinh thi » trinh tai, dinh thi, trinh tu
cong bai » cuong bai, cong hai, cung bai
bai toan » bai tap
toan cau » toan cao, toan ban, toan tap
ho hieu » ho chieu, hoi hieu, nho hieu

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

• Performing a fuzzy search may retrieve terms with similar spellings: ho hieu manh - canh ((tranh thi) OR (trinh thi)) nhung cong bai toan cau~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "ho hieu manh - canh ((tranh thi) OR (trinh thi)) nhung cong bai toan cau".
• Adding a wildcard symbol may retrieve word variants: ho hieu manh - canh ((tranh thi) OR (trinh thi)) nhung cong bai toan cau*.