Perhaps you should try some spelling variations:
tan thanh » tran thanh, tang thanh, toan thanh
thanh va » thanh van, hanh va, thanh ha
su triet » su viet, su tien, ve triet
cua viet » ca viet, hoa viet, cua vat
tu sach » thu sach, su sach, te sach
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: tu sach ky nang ((x hoi) or (x ho)). hieu ve cao duc tan thanh va ((su triet) or (cua viet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang ((x hoi) OR (x ho)). hieu ve cao duc tan thanh va ((su triet) OR (cua viet)).
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang ((x hoi) or (x ho)). hieu ve cao duc tan thanh va ((su triet) or (cua viet))*.