Perhaps you should try some spelling variations:
cham vuc » cham soc, pham duc, cham cuu
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
hieu ve » hieu va, hieu van
ve cham » va cham, ve chat, vu cham
vuc van » duc van, luc van, thuc van
han tai » hang tai, nhan tai, van tai
x hoi » xa hoi, x ho, 5 hoi
o hoi » co hoi, o hoc, o hai
thiet » thieu

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach ky nang ((x hoi) OR (o hoi)). hieu ve cham vuc van ((han tai) or (hang va)) va thiet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky nang ((x hoi) OR (o hoi)). hieu ve cham vuc van ((han tai) OR (hang va)) va thiet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky nang ((x hoi) OR (o hoi)). hieu ve cham vuc van ((han tai) or (hang va)) va thiet".
• Adding a wildcard symbol may retrieve word variants: su sach ky nang ((x hoi) OR (o hoi)). hieu ve cham vuc van ((han tai) or (hang va)) va thiet*.