Perhaps you should try some spelling variations:
tan thanh » tran thanh, tang thanh, toan thanh
cua triet » su triet, va triet
thu sach » tu sach, thuat sach, thuoc sach
thanh va » thanh van, hanh va, thanh ha
cua viet » ca viet, hoa viet, cua vat
sach ky » sac ky, sach y, sach ty
hieu ve » hieu va, hieu van
cao duc » dao duc, cao suc, giao duc
ve cao » va cao, ve bao, ve cac
x hoi » xa hoi, o hoi, 5 hoi

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 ((x hoi) OR (x ho)). hieu ve cao duc tan thanh va ((cua triet) or (cua viet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ky nang ((x hoi) OR (x ho)). hieu ve cao duc tan thanh va ((cua triet) OR (cua viet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ky nang ((x hoi) OR (x ho)). hieu ve cao duc tan thanh va ((cua triet) or (cua viet))".
• Adding a wildcard symbol may retrieve word variants: thu sach ky nang ((x hoi) OR (x ho)). hieu ve cao duc tan thanh va ((cua triet) or (cua viet))*.