Add introduction to the third chapter

config_extra.tex

@@ -50,9 +50,9 @@
     style=numeric-comp, % bib style
     hyperref=true,  % activate hyperref support
     backref=true,   % activate backrefs
-    isbn=false,     % don't show isbn tags
+    isbn=true,      % don't show isbn tags
     url=false,      % don't show url tags
-    doi=false,      % don't show doi tags
+    doi=true,       % don't show doi tags
     urldate=long,   % display type for dates
     maxnames=3,     %
     minnames=1,     %
@@ -72,15 +72,13 @@
   {\endlist}
   {\item}
 
-\AtEveryBibitem{%
-  \clearfield{urlyear}
-  \clearfield{urlmonth}
-  \clearfield{note}
- \clearfield{issn} % Remove issn
- \clearfield{doi} % Remove doi
-\ifentrytype{online}{}{% Remove url except for @online
-  \clearfield{url}
-}
+\DeclareSourcemap{
+  \maps[datatype=bibtex]{
+     \map{
+        \step[fieldsource=doi,final]
+        \step[fieldset=isbn,null]
+        }
+      }
 }
 
 \setlength\bibitemsep{1.1\itemsep}
@@ -146,9 +144,23 @@
 {\savebox\mybox{#1}\begin{quote}\openautoquote\hspace*{-.7ex}}
   {\unskip\closeautoquote\vspace*{1mm}\signed{\usebox\mybox}\end{quote}}
 
+\usepackage[perpage]{footmisc}
+
+\let\myRef\ref
+\renewcommand\ref{\unskip~\myRef}
+
+\let\myEqref\eqref
+\renewcommand\eqref{\unskip~\myEqref}
+
+\let\myCite\cite
+\renewcommand\cite{\unskip~\myCite}
+
 \usepackage{setspace}
 \setstretch{1.25}
 
+\renewcommand{\topfraction}{.8}
+\renewcommand{\floatpagefraction}{.8}
+
 % \setparsizes{0em}{0.1\baselineskip plus .1\baselineskip}{1em plus 1fil}
 
 \numberwithin{equation}{chapter}