Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
hieu viec » nhieu viec, hieu ve, sieu viet
hanh vai » hanh vi, hanh va, hanh tai
cac nuoc » cap nuoc, hoc nuoc, dat nuoc
viec cac » vien cac, viec cua, viec lam
vai cua » dai cua, hai cua, lai cua
va hanh » van hanh, va thanh, va danh
tu sach » thu sach, su sach, te sach
sang ma » tang ma, nang ma, sang tao
vu sach » vu bach, su sach, vu khach

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) or (vu sach)) ky ((nang x) or (sang ma)) hoi. hieu viec cac nuoc va hanh vai cua triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (vu sach)) ky ((nang x) OR (sang ma)) hoi. hieu viec cac nuoc va hanh vai cua triet.
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (vu sach)) ky ((nang x) or (sang ma)) hoi. hieu viec cac nuoc va hanh vai cua triet*.