Perhaps you should try some spelling variations:
sach tru » sach truc, sach thu, sach tu
tru nang » tra nang, tri nang, truc nano
van hanh » van thanh, ban hanh, van anh
cham luc » cham soc, nhan luc, cham cuu
vai cua » dai cua, hai cua, lai cua
luc van » luoc van, luu van, duc van
so sach » so sanh, bo sach, co sach
ve cham » va cham, ve chat, vu cham
hieu ve » hieu va, hieu van
vi cua » di cua
o hoi » co hoi, o hoc, o hai
x hoi » xa hoi, x ho, 5 hoi

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: so sach tru nang ((x hoi) or (o hoi)). hieu ve cham luc van hanh ((vi cua) or (vai cua)) triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach tru nang ((x hoi) OR (o hoi)). hieu ve cham luc van hanh ((vi cua) OR (vai cua)) triet.
• Adding a wildcard symbol may retrieve word variants: so sach tru nang ((x hoi) or (o hoi)). hieu ve cham luc van hanh ((vi cua) or (vai cua)) triet*.