Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
thien van » thi van
cay thuoc » cua thuoc, nam thuoc, va thuoc
nam thuc » nam thuoc, am thuc, nam thu
vanh dai » van dai, vanh tai, lanh dao
sach ty » sach y, sach tu, sach thu
sach ky » sac ky, sach y, sach kem
va vanh » va van, va danh, va hanh
nang o » nang co, nang ho, nang ro
o hoi » co hoi, o hoc, o hai

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) OR (sach ty)) nang o hoi. thien van ((nam thuc) or (cay thuoc)) va vanh dai cua triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach ky) OR (sach ty)) nang o hoi. thien van ((nam thuc) OR (cay thuoc)) va vanh dai cua triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sach ky) OR (sach ty)) nang o hoi. thien van ((nam thuc) or (cay thuoc)) va vanh dai cua triet".
• Adding a wildcard symbol may retrieve word variants: tu ((sach ky) OR (sach ty)) nang o hoi. thien van ((nam thuc) or (cay thuoc)) va vanh dai cua triet*.