Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
toc sach » hoc sach, doc sach, nuoc sach
hieu van » hieu va, thien van, lieu va
nang xa » nang x, lang xa, nang ma
van cam » van nam, van lam, van cau
luu tre » luu tru, cuu tre, luy tre
y nang » ky nang, ly nang, v nang
cam tu » cam thu, nam tu, dam tu
ca dan » cac dan, ca dao
dan vi » doan vi, don vi, dan va
vi luu » vi lua
tu ca » tu cac, tu cua, tu can

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((toc sach) or (thuoc sach)) y nang xa hoi. hieu van cam tu ca dan vi luu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((toc sach) OR (thuoc sach)) y nang xa hoi. hieu van cam tu ca dan vi luu tre.
• Adding a wildcard symbol may retrieve word variants: ((toc sach) or (thuoc sach)) y nang xa hoi. hieu van cam tu ca dan vi luu tre*.