Perhaps you should try some spelling variations:
hanh trinh » canh tranh, hanh chinh
chieu sang » chieu sach, chieu xanh, nhieu tang
thong cong » trong cong, tong cong, thong thong
hieu lang » hieu quang, nhieu tang, hieu van
trinh vat » trinh van, trinh luat, sinh vat
vat thong » va thong, vat trong, mat thong
dan toan » van toan, dan than, manh toan
dan chan » dan gian, dan ca, van chat

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc ((chieu sang) OR (hieu lang)) - hanh trinh vat thong cong ((dan toan) or (dan chan)) ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((chieu sang) OR (hieu lang)) - hanh trinh vat thong cong ((dan toan) OR (dan chan)) ban.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((chieu sang) OR (hieu lang)) - hanh trinh vat thong cong ((dan toan) or (dan chan)) ban".
• Adding a wildcard symbol may retrieve word variants: hoc ((chieu sang) OR (hieu lang)) - hanh trinh vat thong cong ((dan toan) or (dan chan)) ban*.