Perhaps you should try some spelling variations:
thieu nien » thien nhien
hieu vien » hieu hien, hieu viec, hieu tieng
xay thuc » cay thuc, day thuc, xa thuc
vat hanh » vat thanh, van hanh, va hanh
vu sach » vu bach, su sach, vu khach
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
cua tre » cua te, cuu tre, cua triet
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: vu sach ky nang xa hoi. ((hieu vien) OR (thieu nien)) xay thuc vat hanh vi cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu sach ky nang xa hoi. ((hieu vien) OR (thieu nien)) xay thuc vat hanh vi cua tre".
• Adding a wildcard symbol may retrieve word variants: vu sach ky nang xa hoi. ((hieu vien) OR (thieu nien)) xay thuc vat hanh vi cua tre*.