Perhaps you should try some spelling variations:
dau tren » dau tien, dat tren, dau tieng
luc ngan » luc nganh, luc nhan, luat ngan
cam luc » cam xuc, cau luc
hieu va » lieu va, hieu qua
tu sach » thu sach, su sach, te sach
ty hang » ly hang, ty xang, thi hang
ty nang » ky nang, ty xang, ly nang
hieu ve » hieu van
va dau » va dao

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 ((ty nang) or (ty hang)) xa hoi. ((hieu ve) OR (hieu va)) cam luc ngan hang va dau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((ty nang) OR (ty hang)) xa hoi. ((hieu ve) OR (hieu va)) cam luc ngan hang va dau tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((ty nang) or (ty hang)) xa hoi. ((hieu ve) OR (hieu va)) cam luc ngan hang va dau tren".
• Adding a wildcard symbol may retrieve word variants: tu sach ((ty nang) or (ty hang)) xa hoi. ((hieu ve) OR (hieu va)) cam luc ngan hang va dau tren*.