Perhaps you should try some spelling variations:
pham thuc » phap thuc, pham chuc, nham thuc
doan van » doan va, hoang van, luan van
van cua » vang cua, ban cua, dan cua
va doan » va doanh, van doan, va dan
thuc va » thuc vat, thuc dan, thuc day
ve pham » vi pham, v pham, ve phan
hieu ve » hieu va, hieu van
cua tre » cua te, cuu tre, cua triet
sach ky » sac ky, sach ty, sach kem
nang ma » tang ma, sang ma, nang cao
nang xa » nang x, lang xa, mang xa

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

• If you are trying to use Boolean operators, they must be ALL CAPS: te ((sach ky) OR (sach y)) ((nang xa) OR (nang ma)) hoi. hieu ve pham thuc va doan van cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te ((sach ky) or (sach y)) ((nang xa) OR (nang ma)) hoi. hieu ve pham thuc va doan van cua tre~".
• Adding a wildcard symbol may retrieve word variants: te ((sach ky) or (sach y)) ((nang xa) OR (nang ma)) hoi. hieu ve pham thuc va doan van cua tre*.