Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
su triet » su viet, su tien, ve triet
ky dang » ky nang, ky danh
va hanh » van hanh, va thanh, va danh
ky anh » ky danh, ly anh, ty anh
va cam » va cham, va cac, va cao
luc va » duc va, tuc va, loc va
ve cam » ve cham, ve cac, ve cai
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 ((ky dang) or (ky anh)) xa hoi. hieu ((ve cam) or (va cam)) luc va hanh vi su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ((ky dang) OR (ky anh)) xa hoi. hieu ((ve cam) OR (va cam)) luc va hanh vi su triet.
• Adding a wildcard symbol may retrieve word variants: toc sach ((ky dang) or (ky anh)) xa hoi. hieu ((ve cam) or (va cam)) luc va hanh vi su triet*.