Perhaps you should try some spelling variations:
thanh hai » thanh phan, thanh hoa, thanh san
thuc dan » thuc hanh, hoc dan
cua viet » ca viet, hoa viet, cua vat
nang ma » tang ma, sang ma, nang cao
hai cua » thai cua, dai cua, hoi cua
su sac » su sach, su cac, su xac
sac ky » cac ky, sai ky
ve nam » va nam, le nam, te nam
he nam » ha nam, nghe nam

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 nang ma hoa. hieu ((ve nam) OR (he nam)) ((thuc dan) OR (thuc vat)) thanh hai cua viet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sac ky nang ma hoa. hieu ((ve nam) OR (he nam)) ((thuc dan) or (thuc vat)) thanh hai cua viet~".
• Adding a wildcard symbol may retrieve word variants: su sac ky nang ma hoa. hieu ((ve nam) OR (he nam)) ((thuc dan) or (thuc vat)) thanh hai cua viet*.