Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
ve triet » va trien, su triet
ky long » ky cong, sy long, ky trong
hieu ve » hieu van
hieu va » lieu va, hieu qua
cam luc » cam xuc, cau luc
va hanh » van hanh, va thanh, va danh
luc va » duc va, tuc va, loc va
vi ve » va ve, gi ve, ve ve

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 long) or (cay trong)) xa hoi. ((hieu ve) or (hieu va)) cam luc va hanh vi ve triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ((ky long) OR (cay trong)) xa hoi. ((hieu ve) OR (hieu va)) cam luc va hanh vi ve triet.
• Adding a wildcard symbol may retrieve word variants: toc sach ((ky long) or (cay trong)) xa hoi. ((hieu ve) or (hieu va)) cam luc va hanh vi ve triet*.