Perhaps you should try some spelling variations:
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
va hanh » van hanh, va thanh, va danh
luu tre » cuu tre, luy tre
ve cao » va cao, ve cac, ve co
ve bao » te bao, va bao
x hoi » xa hoi, o hoi, x ho
tru » truc

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 x hoi. hieu ((ve cao) or (ve bao)) duc va hanh vi ((luu tre) OR (luu tru))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang x hoi. hieu ((ve cao) OR (ve bao)) duc va hanh vi ((luu tre) OR (luu tru)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang x hoi. hieu ((ve cao) or (ve bao)) duc va hanh vi ((luu tre) OR (luu tru))".
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang x hoi. hieu ((ve cao) or (ve bao)) duc va hanh vi ((luu tre) OR (luu tru))*.