Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
hieu van » hieu va, thien van, lieu va
nam thuc » nam thuoc, am thuc, nam thu
vat tinh » sat tinh, vat sinh, hoat tinh
su sach » so sach, vu sach
nang xa » lang xa, nang ma, mang xa
tinh vi » trinh vi, tinh voi, tinh va
cua tre » cua te, cuu tre, cua triet
vi cua » vai cua, di cua

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) or (su sach)) ky ((nang xa) or (nang x)) hoi. hieu van nam thuc vat tinh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((thu sach) OR (su sach)) ky ((nang xa) OR (nang x)) hoi. hieu van nam thuc vat tinh vi cua tre.
• Adding a wildcard symbol may retrieve word variants: ((thu sach) or (su sach)) ky ((nang xa) or (nang x)) hoi. hieu van nam thuc vat tinh vi cua tre*.