Perhaps you should try some spelling variations:
thuc dan » thuc hanh, hoc dan, thuc vat
sach ky » sac ky, sach y, sach ty
thuc va » thuc vat, thuc day
tu sach » thu sach, su sach, te sach
nang xa » nang x, lang xa, nang ma
cua tre » cua te, cuu tre, cua triet
va cao » va cac, va co, va dao
va cam » va cham, va cac, va cai
dan vi » doan vi, don vi, dan va
vi cua » vai cua, di cua

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

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