Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
van hanh » van thanh, ban hanh, van anh
su triet » su viet, su tien, ve triet
nang xa » nang x, lang xa, nang ma
va dam » van dam, va dau, va dap
va dao » ca dao
tu van » tu va
vi su » va su, ve su, ki su

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: ((toc sach) or (hoc sinh)) ky nang xa hoi. lieu ((va dam) OR (va dao)) tu van hanh vi su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((toc sach) OR (hoc sinh)) ky nang xa hoi. lieu ((va dam) OR (va dao)) tu van hanh vi su triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((toc sach) or (hoc sinh)) ky nang xa hoi. lieu ((va dam) OR (va dao)) tu van hanh vi su triet".
• Adding a wildcard symbol may retrieve word variants: ((toc sach) or (hoc sinh)) ky nang xa hoi. lieu ((va dam) OR (va dao)) tu van hanh vi su triet*.