Perhaps you should try some spelling variations:
pham trinh » pham tinh, pham minh, pham thanh
toc sach » hoc sach, doc sach, thuoc sach
hieu van » hieu va, thien van, lieu va
trinh va » trinh van, trinh vat, trinh ve
lam thuc » lam thuoc, am thuc, nam thuc
cua tre » cua te, cua triet, dua tren
van lam » van nam
sach ky » sac ky, sach y, sach ty
nang xa » lang xa, nang ma, mang xa
cuu tre » cau tren, cau treo

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc sach ky ((nang xa) or (nang x)) hoi. hieu van lam thuc pham trinh va ((cua tre) OR (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ky ((nang xa) OR (nang x)) hoi. hieu van lam thuc pham trinh va ((cua tre) OR (cuu tre)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ky ((nang xa) or (nang x)) hoi. hieu van lam thuc pham trinh va ((cua tre) OR (cuu tre))".
• Adding a wildcard symbol may retrieve word variants: toc sach ky ((nang xa) or (nang x)) hoi. hieu van lam thuc pham trinh va ((cua tre) OR (cuu tre))*.