Perhaps you should try some spelling variations:
cau tren » cu tren, dau tren, ca tren
dong tai » dung tai, luong tai, cong tac
dang cac » dung cac, bang cac, dong cac
cac khoi » cac thoi, cac khoan, cach thoi
thuc day » thuc dan, thuc vat
ky dang » ky nang, ky danh
hieu ve » hieu va, hieu van
ve cham » va cham, ve chat, vu cham
thuc va » thuc vat, thuc dan
cuu tre » cua tre, cau treo
su sac » su sach, su cac, su xac
sac ky » cac ky, sai ky

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: su sac ky dang cac khoi. hieu ve cham ((thuc va) OR (thuc day)) dong tai ((cuu tre) OR (cau tren))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sac ky dang cac khoi. hieu ve cham ((thuc va) OR (thuc day)) dong tai ((cuu tre) or (cau tren))~".
• Adding a wildcard symbol may retrieve word variants: su sac ky dang cac khoi. hieu ve cham ((thuc va) OR (thuc day)) dong tai ((cuu tre) or (cau tren))*.