Perhaps you should try some spelling variations:
pham thuc » phap thuc, pham chuc, nham thuc
nang ma » tang ma, sang ma, nang cao
hieu ve » hieu va, hieu van
ve pham » vi pham, v pham, ve phan
thuc va » thuc vat, thuc dan, thuc day
va doan » va doanh, van doan, va dan
doan vi » doan va, don vi, doan thi
cua tre » cua te, cua triet, dua tren
cuu tre » cau tren, cau treo
tu sac » tu sach, tu cac, tu san
sac ky » cac ky, sai ky
ma hoi » mai hoi, xa hoi, ma hoa

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

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