Perhaps you should try some spelling variations:
ban hanh » ban hang
hoc viet » hoc hien
ky tang » ky nang, ky dang, kho tang
mai hoi » mai khoi, lai hoi, mai doi
dai hoi » dai hoc, dai hai, dai moi
hieu ve » hieu va, hieu van
xuc ban » duc ban, cuc ban, quoc ban
su sai » su tai, su hai, su dai
sai ky » sac ky
ve cam » ve cham, ve cac, va cam
vi hoc » li hoc, va hoc

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sai ky tang ((mai hoi) or (dai hoi)). hieu ve cam xuc ban hanh vi hoc viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sai ky tang ((mai hoi) OR (dai hoi)). hieu ve cam xuc ban hanh vi hoc viet.
• Adding a wildcard symbol may retrieve word variants: su sai ky tang ((mai hoi) or (dai hoi)). hieu ve cam xuc ban hanh vi hoc viet*.