Perhaps you should try some spelling variations:
co sach » bo sach, cuon sach, hoc sach
sach ty » sach y, sach tu, sach thu
ty nang » ky nang, ty xang, ty hang
va danh » va dinh, va dan, va hanh
vai cua » dai cua, hai cua, bai cua
lai cua » dai cua, hai cua, lai chau
v pham » d pham
x hoi » xa hoi, o hoi, x ho

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

• Performing a fuzzy search may retrieve terms with similar spellings: co sach ty nang x hoi. hieu ((v pham) or (vi pham)) duc va danh ((vai cua) OR (lai cua)) te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: co sach ty nang x hoi. hieu ((v pham) OR (vi pham)) duc va danh ((vai cua) OR (lai cua)) te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "co sach ty nang x hoi. hieu ((v pham) or (vi pham)) duc va danh ((vai cua) OR (lai cua)) te".
• Adding a wildcard symbol may retrieve word variants: co sach ty nang x hoi. hieu ((v pham) or (vi pham)) duc va danh ((vai cua) OR (lai cua)) te*.