Perhaps you should try some spelling variations:
tham thuc » nham thuc, pham thuc, tam thuc
cua triet » cua viet, su triet, va triet
van hanh » van thanh, ban hanh, van anh
tu sach » thu sach, su sach, te sach
hoc anh » hoc nganh, hoc nhanh, ngoc anh
hieu ve » hieu va, hieu van
ve tham » va tham, ve cham, vi tham
va hanh » va thanh, va danh, ban hanh
vi cua » vai cua, di cua
x hoi » xa hoi, o hoi, x ho

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 (hoc anh)) ky nang x hoi. hieu ve tham thuc ((va hanh) OR (van hanh)) vi cua triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (hoc anh)) ky nang x hoi. hieu ve tham thuc ((va hanh) OR (van hanh)) vi cua triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (hoc anh)) ky nang x hoi. hieu ve tham thuc ((va hanh) OR (van hanh)) vi cua triet".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (hoc anh)) ky nang x hoi. hieu ve tham thuc ((va hanh) OR (van hanh)) vi cua triet*.