Perhaps you should try some spelling variations:
danh dien » dinh dien, danh kien, danh lien
hieu van » hieu va, thien van, lieu va
van nhan » van phan, van thanh, danh nhan
thuc day » thuc vat
thuc dan » thuc hanh, hoc dan, thuc vat
thu sac » thu sach, thu san, thu xac
danh di » danh du, xanh di, danh gia
cua tre » cua te, cuu tre, cua triet
nang xa » nang x, lang xa, nang ma
sac ky » cac ky, sai ky

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu sac ky nang xa hoi. hieu van nhan ((thuc day) OR (thuc dan)) ((danh di) or (danh dien)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sac ky nang xa hoi. hieu van nhan ((thuc day) OR (thuc dan)) ((danh di) OR (danh dien)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sac ky nang xa hoi. hieu van nhan ((thuc day) OR (thuc dan)) ((danh di) or (danh dien)) cua tre".
• Adding a wildcard symbol may retrieve word variants: thu sac ky nang xa hoi. hieu van nhan ((thuc day) OR (thuc dan)) ((danh di) or (danh dien)) cua tre*.