Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
cau tren » cu tren, ca tren, cau treo
dau tren » dau tien, dat tren, dau tieng
mai hoi » mai khoi, dai hoi, lai hoi
hieu ve » hieu va, hieu van
cam tuc » cam xuc, cam tu, nam thuc
tuc van » thuc van, truc van, tuc va
ma hoi » xa hoi, ma hoa, me hoi
ve cam » ve cham, ve cac, va cam

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu cac ky nang ((ma hoi) or (mai hoi)). hieu ve cam tuc van hanh vi ((cau tren) OR (dau tren))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu cac ky nang ((ma hoi) OR (mai hoi)). hieu ve cam tuc van hanh vi ((cau tren) OR (dau 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 cam tuc van hanh vi ((cau tren) OR (dau tren))*".