Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
cua viet » ca viet, hoa viet, cua vat
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
thuc va » thuc vat, thuc dan, thuc day
hanh di » hanh de, hang di, xanh di
danh di » danh du, xanh di, danh dien
van am » van nam, van lam, van dam

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 van am thuc va ((((hanh di) OR (danh di))) or (hanh vi)) cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang xa hoi. hieu van am thuc va ((((hanh di) OR (danh di))) OR (hanh vi)) cua viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang xa hoi. hieu van am thuc va ((((hanh di) OR (danh di))) or (hanh vi)) cua viet".
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang xa hoi. hieu van am thuc va ((((hanh di) OR (danh di))) or (hanh vi)) cua viet*.