Perhaps you should try some spelling variations:
thien van » thi van
hieu van » hieu va, lieu va, hieu ve
thuc dan » thuc hanh, hoc dan, thuc vat
so sach » so sanh, bo sach, co sach
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
thuc va » thuc vat, thuc day
vi cua » vai cua, di cua
cua te » cua tu

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

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