Perhaps you should try some spelling variations:
nam thuoc » nam thuc, nam thu, nha thuoc
nuoc sach » nguoi sach, hoc sach, cuoc cach
doc sach » hoc sach, toc sach, dac sac
nang xa » nang x, lang xa, nang ma
hieu va » lieu va, hieu qua
cuu tre » cua tre, cau tren, cau treo
va nam » van nam, ha nam, va nay
va dan » ca dan, va dao, va dap
va dau » va dao
va cuu » va cau, va chu, va huu

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((doc sach) OR (nuoc sach)) ky nang xa hoi. hieu va nam thuoc ((va dan) or (va dau)) va cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((doc sach) OR (nuoc sach)) ky nang xa hoi. hieu va nam thuoc ((va dan) OR (va dau)) va cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((doc sach) OR (nuoc sach)) ky nang xa hoi. hieu va nam thuoc ((va dan) or (va dau)) va cuu tre".
• Adding a wildcard symbol may retrieve word variants: ((doc sach) OR (nuoc sach)) ky nang xa hoi. hieu va nam thuoc ((va dan) or (va dau)) va cuu tre*.