Perhaps you should try some spelling variations:
phai trinh » phai sinh, thai tinh, nhai tinh
thuoc phai » thuoc phap, thuc pham, thuoc tai
lam thuoc » nam thuoc, am thuc, cay thuoc
hieu van » hieu va, thien van, lieu va
trinh va » trinh van, trinh vat, trinh ve
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
mang xa » lang xa, mang may, dang xay
van lam » van nam
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: tu sach ky ((mang xa) or (nang x)) hoi. hieu van lam thuoc phai trinh va cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky ((mang xa) OR (nang x)) hoi. hieu van lam thuoc phai trinh va cua tre.
• Adding a wildcard symbol may retrieve word variants: tu sach ky ((mang xa) or (nang x)) hoi. hieu van lam thuoc phai trinh va cua tre*.