Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
hanh tai » thanh tai, hang tai, han tai
tu sach » thu sach, te sach, tu cach
su sach » so sach, vu sach
nang xa » nang x, lang xa, nang ma
hieu va » lieu va, hieu qua
cau luc » cau truc, cau phuc
va hanh » van hanh, va thanh, va danh
cuc tre » duc tre, cua tre, cuu tre
va cau » van cau, va cac, va dau
luc va » duc va, tuc va, loc va

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) or (su sach))) or (toc sach)) ky nang xa hoi. hieu va cau luc va hanh tai cuc tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((((tu sach) OR (su sach))) OR (toc sach)) ky nang xa hoi. hieu va cau luc va hanh tai cuc tre.
• Adding a wildcard symbol may retrieve word variants: ((((tu sach) or (su sach))) or (toc sach)) ky nang xa hoi. hieu va cau luc va hanh tai cuc tre*.