Perhaps you should try some spelling variations:
cau tren » dau tren, ca tren, cau treo
hanh van » thanh van, khanh van, hanh va
van hanh » van thanh, ban hanh, van anh
tuc van » thuc van, truc van, tuc va
cac tuc » cac toc, cac tu, cac tac
hieu ve » hieu va, hieu van
mai hoi » mai khoi, dai hoi, lai hoi
cu tren » tu tren, dua tren
ma hoi » xa hoi, ma hoa, me hoi
ve cac » va cac, vien cac

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

• If you are trying to use Boolean operators, they must be ALL CAPS: tu cac ky nang ((ma hoi) OR (mai hoi)). hieu ve cac tuc van hanh van ((cau tren) OR (cu tren))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu cac ky nang ((ma hoi) or (mai hoi)). hieu ve cac tuc van hanh van ((cau tren) OR (cu tren))~".
• Adding a wildcard symbol may retrieve word variants: tu cac ky nang ((ma hoi) or (mai hoi)). hieu ve cac tuc van hanh van ((cau tren) OR (cu tren))*.