Perhaps you should try some spelling variations:
thong huong » thong thuong, thong duong, thong thong
trien quang » tran quang, tuyen quang, dien quang
hieu quan » hieu qua, lieu quan, thien quan
trinh va » trinh van, trinh vat, trinh vi
trinh ve » trinh he, trinh vi, trinh viet
dan toan » van toan, dan than, manh toan
toan ban » van 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 quan) or (trien quang)) - hanh ((trinh va) OR (trinh ve)) thong huong dan toan ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((hieu quan) OR (trien quang)) - hanh ((trinh va) OR (trinh ve)) thong huong dan toan ban.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((hieu quan) or (trien quang)) - hanh ((trinh va) OR (trinh ve)) thong huong dan toan ban".
• Adding a wildcard symbol may retrieve word variants: hoc ((hieu quan) or (trien quang)) - hanh ((trinh va) OR (trinh ve)) thong huong dan toan ban*.