Perhaps you should try some spelling variations:
hieu vien » hieu hien, hieu viec, thieu nien
hanh vai » hanh vi, hanh va, hanh tai
ton hanh » toan hanh, hon hanh, lon hanh
nang xa » nang x, lang xa, nang ma
sach ty » sach y, sach tu, sach thu
sach ky » sac ky, sach y, sach kem
dai duc » dai dua, mai duc, dai dac
dao duc » giao duc, tao duoc
vai cua » dai cua, hai cua, lai 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: toc ((sach ky) or (sach ty)) nang xa hoi. hieu vien ((dai duc) OR (dao duc)) ton hanh vai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc ((sach ky) OR (sach ty)) nang xa hoi. hieu vien ((dai duc) OR (dao duc)) ton hanh vai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc ((sach ky) or (sach ty)) nang xa hoi. hieu vien ((dai duc) OR (dao duc)) ton hanh vai cua tre".
• Adding a wildcard symbol may retrieve word variants: toc ((sach ky) or (sach ty)) nang xa hoi. hieu vien ((dai duc) OR (dao duc)) ton hanh vai cua tre*.