Perhaps you should try some spelling variations:
pham thuc » phap thuc, pham chuc, nham thuc
te sach » toc sach
sach ky » sac ky, sach y, sach ty
nang ma » sang ma, nang cao, mang may
tang ma » mang may, tang van
hieu vu » hieu va, hieu ve, hieu su
vu pham » su pham, vi pham, vu kham
thuc va » thuc vat, thuc dan, thuc day
cau cua » cau qua, ca cua, cu cua
cua tre » cua te, cuu tre, cua triet
va dat » va dao, va dau, va dap

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sach ky ((nang ma) or (tang ma)) hoi. hieu vu pham thuc va dat cau cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ky ((nang ma) OR (tang ma)) hoi. hieu vu pham thuc va dat cau cua tre.
• Adding a wildcard symbol may retrieve word variants: te sach ky ((nang ma) or (tang ma)) hoi. hieu vu pham thuc va dat cau cua tre*.