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
vai cau » va cau, van cau, vai cac
va danh » va dinh, va dan, va hanh
vu cham » va cham, vu kham, tu cham
hieu vu » hieu va, hieu ve, hieu su
tu sach » thu sach, te sach, tu cach
ly hang » ly quang
ty hang » ty xang, thi hang, thu hang
su sach » so sach, vu sach
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) OR (su sach)) ((ty hang) or (ly hang)) xa hoi. hieu vu cham luc va danh vai cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (su sach)) ((ty hang) OR (ly hang)) xa hoi. hieu vu cham luc va danh vai cau tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) OR (su sach)) ((ty hang) or (ly hang)) xa hoi. hieu vu cham luc va danh vai cau tren".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) OR (su sach)) ((ty hang) or (ly hang)) xa hoi. hieu vu cham luc va danh vai cau tren*.