Perhaps you should try some spelling variations:
su sach » so sach, vu sach
ky lang » ky nang, ky dang, tay lang
ky tang » ky nang, ky dang, kho tang
hieu ve » hieu va, hieu van
cac tuc » cac toc, cac tu, cac tac
va hanh » van hanh, va thanh, va danh
vai cua » dai cua, hai cua, lai cua
ve cac » va cac, vien cac
tuc va » thuc va, truc va, tuc xa
vi cua » di cua

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