Perhaps you should try some spelling variations:
dong hoa » dong hoc, dong co
van hanh » van thanh, ban hanh, van anh
sach ty » sach y, sach tu, sach thu
du chao » du chat, du cacao
hieu du » hien du, hieu su, hiem du
su sach » so sach, vu 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: su sach ty ((nang xa) or (((lang ha) or (dong hoa)))) hoi. hieu du chao xu van hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ty ((nang xa) OR (((lang ha) OR (dong hoa)))) hoi. hieu du chao xu van hanh vi cua tre.
• Adding a wildcard symbol may retrieve word variants: su sach ty ((nang xa) or (((lang ha) or (dong hoa)))) hoi. hieu du chao xu van hanh vi cua tre*.