Perhaps you should try some spelling variations:
tu sach » thu sach, su sach, te sach
ky dang » ky nang
ky danh » ky anh
hieu va » hieu qua
va hanh » van hanh, va thanh, va danh
cu tren » tu tren, dua tren
soc va » hoc va, loc va, doc va
vi cu » vi su, vi xu, vi du

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 ((ky dang) or (ky danh)) xa hoi. ((hieu va) OR (lieu va)) cham soc va hanh vi cu tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((ky dang) OR (ky danh)) xa hoi. ((hieu va) OR (lieu va)) cham soc va hanh vi cu tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((ky dang) or (ky danh)) xa hoi. ((hieu va) OR (lieu va)) cham soc va hanh vi cu tren".
• Adding a wildcard symbol may retrieve word variants: tu sach ((ky dang) or (ky danh)) xa hoi. ((hieu va) OR (lieu va)) cham soc va hanh vi cu tren*.