Perhaps you should try some spelling variations:
vat duong » van duong, mat duong, va duong
thien van » thi van
duong hoi » duong loi, dong hoi, duong noi
hieu van » hieu va, lieu va, hieu ve
nam thuc » nam thuoc, am thuc, nam thu
so sach » so sanh, bo sach, co sach
sach ky » sac ky, sach y, sach ty
hoi cua » hoi chuc
cua tre » cua te, cuu tre, cua triet
x hoi » xa hoi, o hoi, x ho

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: so sach ky nang x hoi. ((hieu van) or (thien van)) nam thuc vat duong hoi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ky nang x hoi. ((hieu van) OR (thien van)) nam thuc vat duong hoi cua tre.
• Adding a wildcard symbol may retrieve word variants: so sach ky nang x hoi. ((hieu van) or (thien van)) nam thuc vat duong hoi cua tre*.