Perhaps you should try some spelling variations:
co sach » bo sach, cuon sach, hoc sach
hieu ve » hieu va, hieu van
ve pham » vi pham, v pham, ve phan
va danh » va dinh, va dan, dia danh
va hanh » van hanh, va thanh, ban hanh
vai cua » dai cua, hai cua, lai cua
y nang » ky nang, ly nang, may nang
v nang » va nang, vu nang, van nang
cua tu » cua tuc, cua su, cua cu

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 ((y nang) OR (v nang)) xa hoi. hieu ve pham duc ((va danh) or (va hanh)) vai cua tu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: co sach ((y nang) OR (v nang)) xa hoi. hieu ve pham duc ((va danh) OR (va hanh)) vai cua tu.
• The words AND, OR and NOT may confuse the search; try adding quotes: "co sach ((y nang) OR (v nang)) xa hoi. hieu ve pham duc ((va danh) or (va hanh)) vai cua tu".
• Adding a wildcard symbol may retrieve word variants: co sach ((y nang) OR (v nang)) xa hoi. hieu ve pham duc ((va danh) or (va hanh)) vai cua tu*.