Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
van hanh » van thanh, ban hanh, van anh
ty nang » ky nang, ty xang, ty hang
nang xa » nang x, lang xa, nang ma
hieu va » lieu va, hieu qua
va cham » va chat, va tham
soc van » hoc van, oc van, sac van
vai cua » hai cua, lai cua, bai cua

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)) ty nang xa hoi. hieu va cham soc van hanh ((vai cua) OR (dai cua)) tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) or (toc sach)) ty nang xa hoi. hieu va cham soc van hanh ((vai cua) OR (dai cua)) tre~".
• Adding a wildcard symbol may retrieve word variants: ((te sach) or (toc sach)) ty nang xa hoi. hieu va cham soc van hanh ((vai cua) OR (dai cua)) tre*.