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
va dan » ca dan, va dao, va dau
dan vi » doan vi, don vi, dan va
vi luu » vi lua

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 va dan vi luu tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((toc sach) OR (thuoc sach)) y nang xa hoi. hieu van cam tu va 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 va dan vi luu tre*.