diff --git a/.gitignore b/.gitignore
index d212ee4..dcd6835 100644
--- a/.gitignore
+++ b/.gitignore
@@ -318,5 +318,5 @@ main.pdf
 
 # ignore build directories
 # these hold all the clutter we do not want to have 
-tmp
-build
\ No newline at end of file
+.tmp
+.build
\ No newline at end of file
diff --git a/.latexmkrc b/.latexmkrc
index 398277b..cd16ee4 100644
--- a/.latexmkrc
+++ b/.latexmkrc
@@ -16,10 +16,10 @@
 
 # Move all axuiliary files to a separate directory, so they do not clutter up the project directory
 $emulate_aux = 1;
-$aux_dir = "tmp";
+$aux_dir = ".tmp";
 
 # Move the compiled files (and synctex) to a separate directory
-$out_dir = 'build';
+$out_dir = '.build';
 
 # command to compile and run
 $pdflatex = 'pdflatex %O -interaction=nonstopmode -shell-escape %S';
diff --git a/README.md b/README.md
index 49abe47..4bc8640 100644
--- a/README.md
+++ b/README.md
@@ -19,7 +19,6 @@ The directories are as follows:
 Acronyms are defined in the file `acros.tex`. Likewise, glossaries are all defined in `glossary.tex`.
 
 ## Build
-
 The project is intended to be build by TexLive through the use of latexmk. This is why there is a custom `.latexmkrc` file specified to keep the build process clean.
 
 ## Dependencies
@@ -27,4 +26,13 @@ This project requires the following:
 - TexLive
 - latexmk (often packaged with TexLive full-scheme)
 - python
-- pygments (python package for minted)
\ No newline at end of file
+- pygments (python package for minted)
+
+## Files created during build
+The build process of latexmk will create two folders for storing temporary cache files for faster rebuilds. The primary folder being `.tmp` which will hold every created .aux file. Additionally the resulting pdf file will be located besides main.tex as well as an index file called `main.synctex.gz` used for indexing between main.tex and main.pdf (unused by VSCode, used by Overleaf).
+
+Build files:
+- main.pdf
+- main.synctex.gz
+- .build/*
+- .tmp/*
\ No newline at end of file
diff --git a/config/bibtex.tex b/config/bibtex.tex
new file mode 100644
index 0000000..1ea1605
--- /dev/null
+++ b/config/bibtex.tex
@@ -0,0 +1 @@
+\bibliographystyle{unsrtnat}   % set listing style of reference sources: Harvard Method
\ No newline at end of file
diff --git a/config/geomerty.tex b/config/geomerty.tex
new file mode 100644
index 0000000..9bb4d85
--- /dev/null
+++ b/config/geomerty.tex
@@ -0,0 +1,15 @@
+% Set page geometry such as: margin, aspect ratio, ...
+% Documentation see: https://texdoc.org/serve/geometry.pdf/0
+\geometry {
+    papername=a4paper,  % size of paper
+    portrait,           % aspect ratio format
+    % margins
+    left=3cm,
+    right=2cm,
+    top=2cm,
+    bottom=2cm,
+    % includes the head of the page, \headheight and \headsep, into total body.
+    includehead,
+    % show a frame around text (for debuging)
+    showframe=false,
+}
\ No newline at end of file
diff --git a/config/pages.tex b/config/pages.tex
index 6e63f00..191f3ad 100644
--- a/config/pages.tex
+++ b/config/pages.tex
@@ -1,12 +1,3 @@
-% set page margins
-\newgeometry {
-    left=3cm,
-    right=2cm,
-    top=2cm,
-    bottom=2cm,
-    includehead
-}
-
 % configure hyper links
 \hypersetup{
     bookmarksopen=false,
@@ -18,6 +9,7 @@
     pdfborder={0 0 0}       % disable border
 }
 
+% translate caption title to german
 \captionsetup*[figure]{name=Bild}
 \captionsetup*[table]{name=Tabelle}
 \captionsetup*[listing]{name=Quelltext}
diff --git a/main.tex b/main.tex
index c5de7b0..486848e 100644
--- a/main.tex
+++ b/main.tex
@@ -1,4 +1,4 @@
-\documentclass[a4paper, 12pt]{article}
+\documentclass[12pt]{article}
 
 % =====================================================================
 % latex packages to use
@@ -24,7 +24,8 @@
 \usepackage{listings}               % code listings
 \usepackage{color}                  % more colors
 \usepackage{tikz}                   % painting
-\usepackage{tikz-imagelabels}       % overlay labels for images 
+\usepackage{tikz-imagelabels}       % overlay labels for images
+\usepackage{cite}                   % citation for bibliography
 
 \makeindex
 \makenomenclature
@@ -33,9 +34,12 @@
 % include acronym definitions
 \input{acros}
 \input{glossary}
+\input{config/bibtex}
 % include file with fixes and workaround
 % as well as special settings
 \input{extra/fixes}
+% article page geometry configuration
+\input{config/geomerty}
 
 \begin{document}
 
@@ -71,4 +75,7 @@
     % include all used chapters
     \input{config/chapter.tex}
 
+    % source references follow content of article
+    \input{pages/page-09-bibliography}
+
 \end{document}
diff --git a/pages/page-09-bibliography.tex b/pages/page-09-bibliography.tex
new file mode 100644
index 0000000..83972fd
--- /dev/null
+++ b/pages/page-09-bibliography.tex
@@ -0,0 +1,35 @@
+% =====================================================================
+% Bilbiography referecnes must be put into refs.bib
+%
+% --------------------------------------------------------
+% Reference a book:
+%
+% @book{reference-name,
+%   author    = {Donald E. Knuth},
+%   year      = {1986},
+%   title     = {The Book},
+%   publisher = {Addison-Wesley Professional}
+%   edition   = {2}
+% }
+%
+% --------------------------------------------------------
+% Reference an article:
+%
+% @article{reference-name,
+%   title     = {Literate Programming},
+%   author    = {Donald E. Knuth},
+%   journal   = {The Computer Journal},
+%   volume    = {27},
+%   number    = {2},
+%   pages     = {97--111},
+%   year      = {1984},
+%   publisher = {Oxford University Press}
+% }
+%
+% --------------------------------------------------------
+% For citing a certain reference within the document use:
+% \cite{reference-name}
+
+\cleardoublepage                            % should start on new empty page
+\addcontentsline{toc}{section}{Literatur}   % add table of contents entry
+\bibliography{refs}                      % Entries are in the refs.bib file
\ No newline at end of file
diff --git a/refs.bib b/refs.bib
new file mode 100644
index 0000000..f53d4cd
--- /dev/null
+++ b/refs.bib
@@ -0,0 +1,9 @@
+%  ____  _ _     _            
+% | __ )(_) |__ | |_ _____  __
+% |  _ \| | '_ \| __/ _ \ \/ /
+% | |_) | | |_) | ||  __/>  < 
+% |____/|_|_.__/ \__\___/_/\_\
+%
+% Biblatex database for storing bibliography entries that can be cited within the document.
+% See: https://www.overleaf.com/learn/latex/Bibliography_management_with_bibtex.
+%
\ No newline at end of file