Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
vu khanh » vu thanh, van khanh, duy khanh
va thanh » gia thanh, ban thanh, va tinh
hoc goc » hoc hoc, hoc nuoc, hoc duoc
va hanh » van hanh, va danh, ban hanh
tu sach » thu sach, su sach, te sach
hieu ve » hieu va, hieu van
lang xa » lang ha, dang xay, lang van
ky lang » ky nang, ky dang, ky tang
vi cua » vai cua, di cua
ve hoc » te hoc, va hoc, vi hoc

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