Perhaps you should try some spelling variations:
trinh quang » tinh quang, trinh quan, tranh quang
hanh trinh » canh tranh, hanh chinh
chieu sang » chieu sach, chieu xanh, hieu lang
quang doan » quan doan, quang hoan, quang toan
phuong van » phong van, phuong lan, phuong va
hieu manh » chieu xanh, hieu nganh, dieu hanh
toan tap » toan ban

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

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