Perhaps you should try some spelling variations:
cua triet » su triet, va triet
cua viet » ca viet, hoa viet, cua vat
nam truc » nam truoc, nam thuc, nam trung
van hanh » van thanh, ban hanh, van anh
truc van » truc va, thuc van, truc ban
hanh va » hang va, hanh vi
sach ky » sach y, sach ty, sach kem
nang o » nang co, nang ho, nang ro
sac ky » cac ky, sai ky
va nam » van nam, ha nam, va nay
o hai » co hai, so hai, o lai

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach ky) OR (sac ky)) nang o hai. lieu va nam truc van hanh va ((cua triet) OR (cua viet))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sach ky) OR (sac ky)) nang o hai. lieu va nam truc van hanh va ((cua triet) or (cua viet))~".
• Adding a wildcard symbol may retrieve word variants: tu ((sach ky) OR (sac ky)) nang o hai. lieu va nam truc van hanh va ((cua triet) or (cua viet))*.