Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
vanh dai » vanh tai, lanh dao, van dao
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
cao cau » co cau, tao cau, ca cau
cao cap » cao chat
truc va » thuc va, thuc vat, trung va
van dai » van dao, van hai, can dai
cua tre » cua te, cuu tre, cua triet

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

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