Perhaps you should try some spelling variations:
hanh trinh » canh tranh, hanh chinh
thong cong » trong cong, tong cong, thong thong
hanh tang » hanh trang, anh tang, hanh mang
cua thong » cua thuong, cua khong, cua tong
yen tinh » tuyen tinh
bai toan » bai tap
ban than » ban thanh, van thanh, ban hang
so yen » so yeu, o yen, su yen

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

• Performing a fuzzy search may retrieve terms with similar spellings: so yen tinh - ((hanh tang) or (hanh trinh)) cua thong cong ((bai toan) or (ban than)) cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so yen tinh - ((hanh tang) OR (hanh trinh)) cua thong cong ((bai toan) OR (ban than)) cao.
• Adding a wildcard symbol may retrieve word variants: so yen tinh - ((hanh tang) or (hanh trinh)) cua thong cong ((bai toan) or (ban than)) cao*.