Perhaps you should try some spelling variations:
trinh doi » trinh do, trinh hoi, tinh doi
sach hay » sach han, sach ha, sach nay
sach kem » hanh kem
doi cua » dai cua, hoi cua
hieu va » lieu va, hieu qua
nang xa » nang x, lang xa, nang ma
cua tre » cua te, cuu tre, cua triet
sac ky » cac ky, sai ky
va nam » van nam, ha nam, va nay
nam tu » nam thu, nam thuc
tu lap » truc lap

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 hay) or (sach kem))) or (sac ky)) nang xa hoi. hieu va nam tu lap trinh doi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((((sach hay) OR (sach kem))) OR (sac ky)) nang xa hoi. hieu va nam tu lap trinh doi cua tre.
• Adding a wildcard symbol may retrieve word variants: tu ((((sach hay) or (sach kem))) or (sac ky)) nang xa hoi. hieu va nam tu lap trinh doi cua tre*.