Perhaps you should try some spelling variations:
vien sach » vien bach, dien sach, viet sach
hieu vien » hieu hien, hieu viec, thieu nien
sach duoc » sach nuoc, sach dao, sach dung
va thanh » gia thanh, ban thanh, va tinh
tu sach » thu sach, su sach, te 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 danh, ban hanh
tai cua » thai cua, tai cuc, tri cua
cua tre » cua te, cuu tre, cua triet

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 ty nang xa hoi. hieu vien sach duoc ((va thanh) or (va hanh)) tai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty nang xa hoi. hieu vien sach duoc ((va thanh) OR (va hanh)) tai cua tre.
• Adding a wildcard symbol may retrieve word variants: tu sach ty nang xa hoi. hieu vien sach duoc ((va thanh) or (va hanh)) tai cua tre*.