Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
van hanh » van thanh, ban hanh, van anh
ve triet » va trien, su triet
tu sach » thu sach, su sach, te sach
nang xa » nang x, lang xa, nang ma
hieu va » lieu va
xuc van » duc van, luc van, vuc van
v nang » va nang, vu nang, van nang
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: ((tu sach) or (toc sach)) v nang xa hoi. ((hieu va) OR (hieu qua)) cam xuc van hanh vi ve triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (toc sach)) v nang xa hoi. ((hieu va) OR (hieu qua)) cam xuc van hanh vi ve triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (toc sach)) v nang xa hoi. ((hieu va) OR (hieu qua)) cam xuc van hanh vi ve triet".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (toc sach)) v nang xa hoi. ((hieu va) OR (hieu qua)) cam xuc van hanh vi ve triet*.