Perhaps you should try some spelling variations:
hoc viet » hoc hien
van hanh » van thanh, ban hanh, van anh
ky tang » ky nang, kho tang, ky trong
ky dang » ky nang, ky danh
dai hoi » dai hoc, dai hai, dai moi
hieu ve » hieu va, hieu van
xuc van » duc van, luc van, vuc van
su hai » su tai
ve cam » ve cham, ve cac, va cam
vi hoc » li hoc, va hoc
su sai » su tai, su dai, su mai

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) or (su hai)) ((ky tang) or (ky dang)) dai hoi. hieu ve cam xuc van hanh vi hoc viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sai) OR (su hai)) ((ky tang) OR (ky dang)) dai hoi. hieu ve cam xuc van hanh vi hoc viet.
• Adding a wildcard symbol may retrieve word variants: ((su sai) or (su hai)) ((ky tang) or (ky dang)) dai hoi. hieu ve cam xuc van hanh vi hoc viet*.