Perhaps you should try some spelling variations:
va thanh » gia thanh, ban thanh, va tinh
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
hieu ve » hieu va, hieu van
ve pham » vi pham, v pham, ve phan
va hanh » van hanh, va danh, ban hanh
cua tre » cua te, cuu tre, cua triet
sai ky » sac ky
vi cua » vai 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: tu ((sach ky) or (sai ky)) nang xa hoi. hieu ve pham duc ((va hanh) OR (va thanh)) vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach ky) OR (sai ky)) nang xa hoi. hieu ve pham duc ((va hanh) OR (va thanh)) vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sach ky) or (sai ky)) nang xa hoi. hieu ve pham duc ((va hanh) OR (va thanh)) vi cua tre".
• Adding a wildcard symbol may retrieve word variants: tu ((sach ky) or (sai ky)) nang xa hoi. hieu ve pham duc ((va hanh) OR (va thanh)) vi cua tre*.