Perhaps you should try some spelling variations:
thieu nien » thien nhien
bieu hien » dieu hien, dieu khien, bien phien
cac thoi » cac toi, cac hop, cac tro
sach ty » sach y, sach tu, sach thu
va hanh » van hanh, va thanh, va danh
tu sach » thu sach, su sach, te sach
ty nang » ky nang, ty xang, ty hang
cuu tre » cua tre, cau tren, cau treo
cac tu » cac thu, cach tu, cac du
nang o » nang co, nang ho, nang ro
vi cuu » vi luu, vinh cuu
o hoi » co hoi, o hoc, o hai

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 o hoi. ((thieu nien) or (bieu hien)) ((cac tu) or (cac thoi)) va hanh vi cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty nang o hoi. ((thieu nien) OR (bieu hien)) ((cac tu) OR (cac thoi)) va hanh vi cuu tre.
• Adding a wildcard symbol may retrieve word variants: tu sach ty nang o hoi. ((thieu nien) or (bieu hien)) ((cac tu) or (cac thoi)) va hanh vi cuu tre*.