Perhaps you should try some spelling variations:
hieu cao » chieu cao, hieu cac, hieu ca
vanh dai » vanh tai, lanh dao, van dao
sach ky » sach y, sach ty, sach kem
nang xa » nang x, lang xa, nang ma
cao cau » cao cap, co cau, tao cau
truc va » thuc va, thuc vat, trung va
van dai » van dao, van hai, can dai
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: thu ((sach ky) OR (sac ky)) nang xa hoi. hieu cao cau truc va ((vanh dai) or (van dai)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu ((sach ky) OR (sac ky)) nang xa hoi. hieu cao cau truc va ((vanh dai) OR (van dai)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu ((sach ky) OR (sac ky)) nang xa hoi. hieu cao cau truc va ((vanh dai) or (van dai)) cua tre".
• Adding a wildcard symbol may retrieve word variants: thu ((sach ky) OR (sac ky)) nang xa hoi. hieu cao cau truc va ((vanh dai) or (van dai)) cua tre*.