Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
toc sach » hoc sach, doc sach, thuoc sach
hanh tai » thanh tai, hang tai, han tai
van hanh » van thanh, ban hanh, van anh
tai cua » thai cua, tai cuc, tri cua
luc van » luoc van, luu van, duc van
da nang » cam nang, kha nang, cao nang
hieu da » hieu dac, hieu dia, hieu va
tu sach » thu sach, su sach, te sach
hoc hai » hoc dai, hoc bai, hoc tai
ky tang » ky nang, ky dang, kho tang
ho hai » pho hai, cho hai, ho hap

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) OR (toc sach)) ky tang ((ho hai) OR (hoc hai)). hieu da nang luc van hanh tai cua triet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (toc sach)) ky tang ((ho hai) OR (hoc hai)). hieu da nang luc van hanh tai cua triet~".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (toc sach)) ky tang ((ho hai) OR (hoc hai)). hieu da nang luc van hanh tai cua triet*.