Perhaps you should try some spelling variations:
va thanh » gia thanh, ban thanh, va tinh
su sach » so sach, vu sach
ky lang » ky dang, ky tang, tay lang
hieu ve » hieu va, hieu van
cac loc » cac lop, cac toc, cac hoc
ve cac » va cac, vien cac
loc va » hoc va, luc va
vi cua » vai cua
di cua » dai cua, doi cua, de cua

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

• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ((ky lang) OR (ky nang)) xa hoi. hieu ve cac loc va thanh ((vi cua) OR (di cua)) viet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ((ky lang) or (ky nang)) xa hoi. hieu ve cac loc va thanh ((vi cua) OR (di cua)) viet~".
• Adding a wildcard symbol may retrieve word variants: su sach ((ky lang) or (ky nang)) xa hoi. hieu ve cac loc va thanh ((vi cua) OR (di cua)) viet*.