Perhaps you should try some spelling variations:
thanh hai » thanh phan, thanh hoa, thanh san
thuc day » thuc dan, thuc vat
hieu van » hieu va, thien van, lieu va
truc va » thuc va, thuc vat, trung va
hai cuu » hai cua, hai chu, hai cuc
cuu tre » cua tre, cau tren, cau treo
van dau » van dao, phan dau
nang xa » nang x, lang xa, nang ma
san ky » sang ky, van ky, ban ky
dan ky » van 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 ((san ky) OR (dan ky)) nang xa hoi. hieu van dau ((truc va) or (thuc day)) thanh hai cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((san ky) OR (dan ky)) nang xa hoi. hieu van dau ((truc va) OR (thuc day)) thanh hai cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((san ky) OR (dan ky)) nang xa hoi. hieu van dau ((truc va) or (thuc day)) thanh hai cuu tre".
• Adding a wildcard symbol may retrieve word variants: tu ((san ky) OR (dan ky)) nang xa hoi. hieu van dau ((truc va) or (thuc day)) thanh hai cuu tre*.