Perhaps you should try some spelling variations:
cac truc » cau truc, cac tru, cac trung
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
truc va » thuc va, thuc vat, trung va
va hanh » van hanh, va thanh, va danh
ve cac » va cac, vien cac
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 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 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 va hanh vi su triet*.