Perhaps you should try some spelling variations:
nhan luc » nang luc
tu sach » thu sach, su sach, te sach
va hanh » van hanh, va thanh, va danh
de nhan » do nhan, tue nhan, de thanh
hieu de » hieu ve, hieu he, hieu le
ty hang » ly hang, thi hang, thu hang
luc va » duc va, tuc va, loc va
va cau » van cau, va dau, va cao

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