Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
tu sach » thu sach, te sach, tu cach
hang di » hang doi, hang vi, hang dien
va hang » van hang, va nang, va lang
cac luc » cau luc, coc luc, cac nuoc
hieu va » lieu va, hieu qua
lang xa » lang ha, dang xay, lang van
ky lang » ky nang, ky dang, ky tang
su sach » so sach, vu sach
cua tre » cua te, cuu tre, cua triet
luc va » duc va, tuc va, loc va
di cua » dai cua, doi cua, de cua

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