Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
kho tang » cao tang
ve cham » va cham, ve chat, vu cham
ky tang » ky nang, ky dang, ky trong
tuc van » thuc van, truc van, tuc va
mai hoi » mai khoi, dai hoi, lai hoi
su bac » xu bac, du bac, su cac
ve cac » va cac, vien cac
vi hoa » voi hoa, vi hoc, va hoa

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

• Performing a fuzzy search may retrieve terms with similar spellings: su bac ((ky tang) OR (kho tang)) mai hoi. hieu ((ve cac) or (ve cham)) tuc van hanh vi hoa viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su bac ((ky tang) OR (kho tang)) mai hoi. hieu ((ve cac) OR (ve cham)) tuc van hanh vi hoa viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su bac ((ky tang) OR (kho tang)) mai hoi. hieu ((ve cac) or (ve cham)) tuc van hanh vi hoa viet".
• Adding a wildcard symbol may retrieve word variants: su bac ((ky tang) OR (kho tang)) mai hoi. hieu ((ve cac) or (ve cham)) tuc van hanh vi hoa viet*.