Perhaps you should try some spelling variations:
va trien » va truyen, va thiet, va tuyen
thu sach » thuat sach, thuoc sach, thu hoach
va triet » va thiet, ve triet, cua triet
hanh tai » thanh tai, hang tai, han tai
tan hanh » tan thanh, tang hanh, toan hanh
cao duc » dao duc, cao suc, giao duc
tu sach » su sach, te sach, tu cach
hieu ve » hieu va, hieu van
ve cao » va cao, ve bao, ve cac
x hoi » xa hoi, o hoi, x ho

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