Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
qua pham » quan pham, quy pham, qua cham
hoc sach » hoc sinh, hoc anh
van hanh » van thanh, ban hanh, van anh
tu sach » thu sach, su sach, te sach
hoc cac » hoc cao
duc van » duc va, duc tan, duc manh
hanh di » hanh vi, hanh de, hang di
di cua » dai cua, doi cua, de cua

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 (((hoc sach) OR (hoc cac)))) ky nang x ho. hieu qua pham duc van hanh di cua triet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (((hoc sach) OR (hoc cac)))) ky nang x ho. hieu qua pham duc van hanh di cua triet~".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (((hoc sach) OR (hoc cac)))) ky nang x ho. hieu qua pham duc van hanh di cua triet*.