Perhaps you should try some spelling variations:
dong hoa » dong hoc, dong co
van hanh » van thanh, ban hanh, van anh
cacao xu » chao xu, cach xu
sach ty » sach y, sach tu, sach thu
hieu du » hien du, hieu su, hiem du
so sach » so sanh, bo sach, co sach
lang ha » long ha
nang xa » nang x, lang xa, nang ma
cua tre » cua te, cuu tre, cua triet
xu van » tu van, vu van, su van
vi cua » vai cua, di cua

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 xa) or (((lang ha) or (dong hoa)))) hoi. hieu du cacao xu van hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ty ((nang xa) OR (((lang ha) OR (dong hoa)))) hoi. hieu du cacao xu van hanh vi cua tre.
• Adding a wildcard symbol may retrieve word variants: so sach ty ((nang xa) or (((lang ha) or (dong hoa)))) hoi. hieu du cacao xu van hanh vi cua tre*.