Perhaps you should try some spelling variations:
sach hoi » sach doi, sach moi, cach thoi
hoi nang » hoi lang, ho nang, hoa nang
qua cham » qua hai, qua cac, va cham
hanh hoi » hanh thoi, hanh noi, hanh moi
hanh hoa » thanh hoa, khanh hoa, hang hoa
tu sach » thu sach, su sach, te sach
nang xa » nang x, lang xa, nang ma
soc van » hoc van, sac van, soc dan
cua tre » cua te, cuu tre, cua triet
oc van » hoc van, luoc van, quoc van

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 hoi nang xa hoi. hieu qua cham ((soc van) or (oc van)) ((hanh hoi) OR (hanh hoa)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach hoi nang xa hoi. hieu qua cham ((soc van) OR (oc van)) ((hanh hoi) OR (hanh hoa)) cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach hoi nang xa hoi. hieu qua cham ((soc van) or (oc van)) ((hanh hoi) OR (hanh hoa)) cua tre*".