Perhaps you should try some spelling variations:
cua triet » su triet, va triet
cua viet » ca viet, hoa viet, cua vat
toc sach » hoc sach, doc sach, thuoc sach
chat duc » chat xuc, chat doc, chet duoc
va chat » van chat, va phat, cao chat
hieu va » lieu va, hieu qua
v nang » va nang, vu nang, van nang
va dan » ca dan, va dao, va dau
dan vi » doan vi, don vi, dan va
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: ((te sach) OR (toc sach)) v nang x hoi. hieu va chat duc va dan vi ((cua triet) or (cua viet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (toc sach)) v nang x hoi. hieu va chat duc va dan vi ((cua triet) OR (cua viet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) OR (toc sach)) v nang x hoi. hieu va chat duc va dan vi ((cua triet) or (cua viet))".
• Adding a wildcard symbol may retrieve word variants: ((te sach) OR (toc sach)) v nang x hoi. hieu va chat duc va dan vi ((cua triet) or (cua viet))*.