Perhaps you should try some spelling variations:
hoc viet » hoc hien
van hanh » van thanh, ban hanh, van anh
hieu va » lieu va, hieu qua
hanh va » hang va, hanh vi
ky tang » ky nang, ky dang, kho tang
tang xa » trang xa, tang ma, lang xa
hieu ve » hieu van
tuc van » thuc van, truc van, tuc va
cam tuc » cam xuc, cam tu, nam thuc
va hoc » van hoc
su sai » su tai, su dai, su mai
su hai » su tai

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 xa hoi. ((hieu ve) or (hieu va)) cam tuc van hanh va hoc viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sai) OR (su hai)) ky tang xa hoi. ((hieu ve) OR (hieu va)) cam tuc van hanh va hoc viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su sai) OR (su hai)) ky tang xa hoi. ((hieu ve) or (hieu va)) cam tuc van hanh va hoc viet".
• Adding a wildcard symbol may retrieve word variants: ((su sai) OR (su hai)) ky tang xa hoi. ((hieu ve) or (hieu va)) cam tuc van hanh va hoc viet*.