Perhaps you should try some spelling variations:
va thanh » gia thanh, ban thanh, va tinh
bo sach » co sach, hoc sach
va hanh » van hanh, va danh, ban hanh
cao loc » cao hoc, cao toc, cao oc
hieu va » lieu va, hieu qua
ky danh » ky anh
ky dang » ky nang
va cao » va cac, va co, va dao
vi cua » vai cua, di cua
cua te » cua tu

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

• Performing a fuzzy search may retrieve terms with similar spellings: bo sach ((ky dang) or (ky danh)) xa hoi. hieu va cao loc ((va hanh) OR (va thanh)) vi cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: bo sach ((ky dang) OR (ky danh)) xa hoi. hieu va cao loc ((va hanh) OR (va thanh)) vi cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "bo sach ((ky dang) or (ky danh)) xa hoi. hieu va cao loc ((va hanh) OR (va thanh)) vi cua te".
• Adding a wildcard symbol may retrieve word variants: bo sach ((ky dang) or (ky danh)) xa hoi. hieu va cao loc ((va hanh) OR (va thanh)) vi cua te*.