Perhaps you should try some spelling variations:
pham thuc » phap thuc, pham chuc, nham thuc
ky sang » ky nang, ky dang, ky tang
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, cuu tre, cua triet
tu sac » tu sach, tu cac, tu san
sac ky » cac ky, sai ky
ma hoi » mai hoi, xa hoi, me hoi
vi cua » vai cua, di 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 sac ky sang ((ma hoi) or (ma hoa)). hieu ve pham thuc va doan vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sac ky sang ((ma hoi) OR (ma hoa)). hieu ve pham thuc va doan vi cua tre.
• Adding a wildcard symbol may retrieve word variants: tu sac ky sang ((ma hoi) or (ma hoa)). hieu ve pham thuc va doan vi cua tre*.