Perhaps you should try some spelling variations:
chet duoc » che duoc, cho duoc, che quoc
cua triet » su triet
hieu van » hieu va, thien van, lieu va
van chet » van chat, van chuyet, van chien
va triet » va thiet, va trien, 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
nang xa » nang x, lang xa, nang ma
duoc va » nuoc va, duc va, duoc ma
dan day » da day, dan dat, dan da
va dan » ca dan, va dao, va dau

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 xa hoi. hieu van chet duoc va dan day ((((cua triet) or (va triet))) or (cua viet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang xa hoi. hieu van chet duoc va dan day ((((cua triet) OR (va triet))) OR (cua viet)).
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang xa hoi. hieu van chet duoc va dan day ((((cua triet) or (va triet))) or (cua viet))*.