Perhaps you should try some spelling variations:
cac truc » cac tru, cac trung, sach truc
su triet » su viet, su tien, ve triet
so sach » so sanh, bo sach, co sach
sach ty » sach y, sach tu, sach thu
hieu ve » hieu va, hieu van
va hanh » van hanh, va thanh, va danh
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: so sach ty ((xang x) or (nang x)) hoi. hieu ve ((cac truc) OR (cau truc)) va hanh vi su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ty ((xang x) OR (nang x)) hoi. hieu ve ((cac truc) OR (cau truc)) va hanh vi su triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach ty ((xang x) or (nang x)) hoi. hieu ve ((cac truc) OR (cau truc)) va hanh vi su triet".
• Adding a wildcard symbol may retrieve word variants: so sach ty ((xang x) or (nang x)) hoi. hieu ve ((cac truc) OR (cau truc)) va hanh vi su triet*.