Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
toc sach » hoc sach, doc sach, thuoc sach
hieu va » lieu va, hieu qua
cac duc » cac du, cao duc, cac dac
va tinh » may tinh
tinh di » tinh doi, trinh di, tinh da
y xang » ty xang
xang x » nang x
cua te » cua tu
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)) y xang x hoi. hieu va cac duc va tinh di ((cua te) or (cua triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (toc sach)) y xang x hoi. hieu va cac duc va tinh di ((cua te) OR (cua triet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) OR (toc sach)) y xang x hoi. hieu va cac duc va tinh di ((cua te) or (cua triet))".
• Adding a wildcard symbol may retrieve word variants: ((te sach) OR (toc sach)) y xang x hoi. hieu va cac duc va tinh di ((cua te) or (cua triet))*.