Perhaps you should try some spelling variations:
pham thuc » phap thuc, pham chuc, nham thuc
doan thi » dan thi, doanh tai, hoang thi
cuu tre » cua tre, cau tren, cau treo
thuc va » thuc vat, thuc dan, thuc day
hieu ve » hieu va, hieu van
ve pham » vi pham, v pham, ve phan
tang ma » mang may, tang van
sang ma » nang ma, sang tao, mang may
sac ky » cac ky, sai ky
dan vi » doan vi, don vi, dan va
tu sac » tu sach, tu cac, tu san

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) or (tang ma)) hoi. hieu ve pham thuc va ((dan vi) or (doan thi)) cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sac ky ((sang ma) OR (tang ma)) hoi. hieu ve pham thuc va ((dan vi) OR (doan thi)) cuu tre.
• Adding a wildcard symbol may retrieve word variants: tu sac ky ((sang ma) or (tang ma)) hoi. hieu ve pham thuc va ((dan vi) or (doan thi)) cuu tre*.