Perhaps you should try some spelling variations:
thien chien » thien nhien
hieu vien » hieu hien, hieu viec, thieu nien
van hanh » van thanh, ban hanh, van anh
sach ty » sach y, sach tu, sach thu
va hanh » va thanh, va danh, ban hanh
cac thu » cach thuc, cac thoi
so sach » so sanh, bo sach, co sach
ty nang » ky nang, ty xang, ty hang
cua tre » cua te, cuu tre, cua triet
nang o » nang co, nang ho, nang ro
vi cua » vai cua, di cua
o hoc » co hoc, mo hoc, so hoc

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 o hoc. ((hieu vien) or (thien chien)) cac thu ((va hanh) or (van hanh)) vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ty nang o hoc. ((hieu vien) OR (thien chien)) cac thu ((va hanh) OR (van hanh)) vi cua tre.
• Adding a wildcard symbol may retrieve word variants: so sach ty nang o hoc. ((hieu vien) or (thien chien)) cac thu ((va hanh) or (van hanh)) vi cua tre*.