Perhaps you should try some spelling variations:
thanh do » thanh de, thanh pho, thanh hoa
va thanh » gia thanh, ban thanh, va tinh
hieu van » hieu va, thien van, lieu va
truc va » thuc va, thuc vat, trung va
van cau » van dau, van hau, van chat
cua tre » cua te, cuu tre, cua triet
sach ky » sac ky, sach ty, sach kem
nang xa » lang xa, nang ma, mang xa
do cua » doi cua, co cua, de 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 ky) OR (sach y)) ((nang xa) or (nang x)) hoi. hieu van cau truc va thanh do cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sach ky) OR (sach y)) ((nang xa) OR (nang x)) hoi. hieu van cau truc va thanh do cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su ((sach ky) OR (sach y)) ((nang xa) or (nang x)) hoi. hieu van cau truc va thanh do cua tre".
• Adding a wildcard symbol may retrieve word variants: su ((sach ky) OR (sach y)) ((nang xa) or (nang x)) hoi. hieu van cau truc va thanh do cua tre*.