Perhaps you should try some spelling variations:
hieu quan » lieu quan, thien quan, lien quan
ban hanh » ban hang
so sach » so sanh, bo sach, co sach
sach ty » sach y, sach tu, sach thu
ty nang » ky nang, ty xang, ty hang
nang xa » nang x, lang xa, nang ma
va hanh » van hanh, va thanh, va danh
cua tre » cua te, cuu tre, cua triet
vi cua » vai cua, di cua
nuoc » quoc, duoc, ngoc

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

• Performing a fuzzy search may retrieve terms with similar spellings: so sach ty nang xa hoi. ((hieu quan) or (hieu qua)) hoc nuoc ((va hanh) or (ban hanh)) vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ty nang xa hoi. ((hieu quan) OR (hieu qua)) hoc nuoc ((va hanh) OR (ban hanh)) vi cua tre.
• Adding a wildcard symbol may retrieve word variants: so sach ty nang xa hoi. ((hieu quan) or (hieu qua)) hoc nuoc ((va hanh) or (ban hanh)) vi cua tre*.