Perhaps you should try some spelling variations:
thanh va » thanh van, hanh va, thanh ha
da thanh » dao thanh, dat thanh, dam thanh
cam thuc » nam thuc, cam thu, can thuc
su sach » so sach, vu sach
sach ty » sach y, sach tu, sach thu
hieu ve » hieu va, hieu van
lang xa » lang ha, dang xay, lang van
nang xa » nang x, nang ma, mang xa
cua tre » cua te, cuu tre, cua triet
va cua » va chua, via cua, ca 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 ty ((nang xa) OR (lang xa)) hoi. hieu ve ((cam thuc) or (am thuc)) da thanh va cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ty ((nang xa) OR (lang xa)) hoi. hieu ve ((cam thuc) OR (am thuc)) da thanh va cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ty ((nang xa) OR (lang xa)) hoi. hieu ve ((cam thuc) or (am thuc)) da thanh va cua tre*".