Entity not defined

I am switching from instant saxton to xsltproc and I cannot get xsltproc parsing. It considers text entities as invalid. I did not see any help to what I have wrong. I get errors like:

xml:3196: parser error : Entity 'rdquo' not defined

enter a value of &ldquo;<emphasis role="bold">60</emphasis>&rdquo;
                                                                 ^
xml:3242: parser error : Entity 'ldquo' not defined

s> file. Add the Technical Manual, similar to this format. &ldquo;

xsltproc --output myfile.html --stringparam use.extension 0 ..\docbook-xsl-1.68.1\docbook-html.xsl UserGuideSGML.xml

xmllint --xinclude UserGuideSGML.xml

Thanks... 

Douglas