Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
cham luc » cham soc, nhan luc, cham cuu
hieu va » lieu va, hieu qua
va cham » va chat, va tham
va hanh » van hanh, va thanh, va danh
luu tre » cuu tre, luy tre
luc va » duc va, tuc va, loc va
x hoi » xa hoi, o hoi, x ho
tru » truc

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

• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (toc sach)) ky nang x hoi. hieu va cham luc va hanh vi ((luu tre) OR (luu tru))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) or (toc sach)) ky nang x hoi. hieu va cham luc va hanh vi ((luu tre) OR (luu tru))~".
• Adding a wildcard symbol may retrieve word variants: ((te sach) or (toc sach)) ky nang x hoi. hieu va cham luc va hanh vi ((luu tre) OR (luu tru))*.