Perhaps you should try some spelling variations:
pham thuc » phap thuc, pham chuc, nham thuc
doan thi » dan thi, doanh tai, hoang thi
hieu ve » hieu va, hieu van
thi cua » thai cua, thi cuc, tri 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
cua tre » cua te, cuu tre, cua triet
mai hoi » mai khoi, dai hoi, lai hoi
ky sang » ky nang, ky dang, ky tang
san ky » sang ky, van ky, dan ky
ma hoi » xa hoi, me hoi, va hoi
tu san » thu san, tu ban, tu can

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

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