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
su sach » so sach, vu sach
truc va » thuc va, thuc vat, trung va
hai cuc » tai cuc, hai cua, thai cua
van cau » van dau, van hau, van chat
sach ky » sac ky, sach y, sach ty
lang xa » lang ha, dang xay, lang van
nang xa » nang x, nang ma, mang xa
cuc tre » duc tre, cua tre, cuu tre

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 ky ((nang xa) OR (lang xa)) hoi. hieu van cau ((truc va) or (thuc day)) thanh hai cuc tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky ((nang xa) OR (lang xa)) hoi. hieu van cau ((truc va) OR (thuc day)) thanh hai cuc tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky ((nang xa) OR (lang xa)) hoi. hieu van cau ((truc va) or (thuc day)) thanh hai cuc tre".
• Adding a wildcard symbol may retrieve word variants: su sach ky ((nang xa) OR (lang xa)) hoi. hieu van cau ((truc va) or (thuc day)) thanh hai cuc tre*.