Perhaps you should try some spelling variations:
bach tuoc » sach duoc, sach nuoc
hieu vien » hieu viec, thieu nien, hieu tieng
hieu hien » bieu hien, dieu hien, chieu chien
va hanh » van hanh, va thanh, va danh
va banh » va ban, va danh, va benh
su sach » so sach, vu sach
sach ty » sach y, sach tu, sach thu
nang xa » nang x, lang xa, nang ma
ty nang » ky nang, ty xang, ty hang
cua tre » cua te, cuu tre, cua triet
di cua » dai cua, doi cua, de cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach ty nang xa hoi. ((hieu vien) OR (hieu hien)) bach tuoc ((va banh) or (va hanh)) di cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ty nang xa hoi. ((hieu vien) OR (hieu hien)) bach tuoc ((va banh) OR (va hanh)) di cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ty nang xa hoi. ((hieu vien) OR (hieu hien)) bach tuoc ((va banh) or (va hanh)) di cua tre".
• Adding a wildcard symbol may retrieve word variants: su sach ty nang xa hoi. ((hieu vien) OR (hieu hien)) bach tuoc ((va banh) or (va hanh)) di cua tre*.