Perhaps you should try some spelling variations:
tham thuc » nham thuc, pham thuc, tam thuc
danh kien » dinh kien, danh viet, linh kien
kien cua » khien cua, dien cua, tien cua
sach ky » sac ky, sach ty, sach kem
nang xa » nang x, lang xa, nang ma
va tham » van tham, va cham, va thanh
thuc va » thuc vat, thuc dan, thuc day
va danh » va dinh, va dan, va hanh
cua tre » cua te, cuu tre, cua triet

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

• Performing a fuzzy search may retrieve terms with similar spellings: doc ((sach ky) or (sach y)) nang xa hoi. lieu va tham thuc va danh kien cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc ((sach ky) OR (sach y)) nang xa hoi. lieu va tham thuc va danh kien cua tre.
• Adding a wildcard symbol may retrieve word variants: doc ((sach ky) or (sach y)) nang xa hoi. lieu va tham thuc va danh kien cua tre*.