Perhaps you should try some spelling variations:
hanh hai » thanh hai, nhanh hai, hang hai
trung ha » trung hoc, trung tam, trung cap
hieu van » hieu va, thien van, lieu va
van chat » cao chat
sach thu » sach thue, sach thieu, sach tham
hai cua » thai cua, dai cua, hoi cua
truc va » thuc va, thuc vat, trung va
nang xa » nang x, lang xa, nang ma
cua tre » cua te, cuu tre, cua triet
sac ky » cac ky, sai ky

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 thu) or (sac ky)) nang xa hoi. hieu van chat ((truc va) or (trung ha)) hanh hai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach thu) OR (sac ky)) nang xa hoi. hieu van chat ((truc va) OR (trung ha)) hanh hai cua tre.
• Adding a wildcard symbol may retrieve word variants: tu ((sach thu) or (sac ky)) nang xa hoi. hieu van chat ((truc va) or (trung ha)) hanh hai cua tre*.