Perhaps you should try some spelling variations:
voi hoat » toi hoat, doi hoat, vo hoat
van hanh » van thanh, ban hanh, van anh
xuc van » duc van, luc van, vuc van
voi hoa » voi khoa, boi hoa, voi ho
su sach » so sach, vu sach
hieu ve » hieu va, hieu van
cac xuc » cam xuc, cac nuoc, chat xuc
ve cac » va cac, vien cac
y nang » ky nang, ly nang, v nang
ma hoi » mai hoi, xa hoi, me hoi

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach y nang ((ma hoi) OR (ma hoa)). hieu ve cac xuc van hanh ((voi hoa) or (voi hoat)) viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach y nang ((ma hoi) OR (ma hoa)). hieu ve cac xuc van hanh ((voi hoa) OR (voi hoat)) viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach y nang ((ma hoi) OR (ma hoa)). hieu ve cac xuc van hanh ((voi hoa) or (voi hoat)) viet".
• Adding a wildcard symbol may retrieve word variants: su sach y nang ((ma hoi) OR (ma hoa)). hieu ve cac xuc van hanh ((voi hoa) or (voi hoat)) viet*.