Perhaps you should try some spelling variations:
dam thuc » am thuc, dan thuc, dai thuc
nam thuc » nam thuoc, am thuc, nam thu
hanh vai » hanh vi, hanh va, hanh tai
cua viet » ca viet, cua vat, cua dieu
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
hieu ve » hieu va, hieu van
va hanh » van hanh, va thanh, va danh

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

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