Perhaps you should try some spelling variations:
cau tren » cu tren, dau tren, ca tren
danh vai » danh sai, danh va, doanh van
cham luc » cham soc, nhan luc, cham cuu
hieu va » lieu va, hieu qua
vai cau » va cau, van cau, vai cac
va danh » va dinh, va dan, va hanh
tu sach » thu sach, su sach, te sach
hieu vu » hieu ve, hieu su, dieu vu
ly hang » ly quang
ty hang » ty xang, thi hang, thu hang
luc va » duc va, tuc va, loc va

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