add more citation

doc/wine_refs.bib

@@ -6,16 +6,16 @@ @Manual{here
     url = {https://CRAN.R-project.org/package=here}
 }
 
-@article{sk-learn,
- title={Scikit-learn: Machine Learning in {P}ython},
- author={Pedregosa, F. and Varoquaux, G. and Gramfort, A. and Michel, V.
-         and Thirion, B. and Grisel, O. and Blondel, M. and Prettenhofer, P.
-         and Weiss, R. and Dubourg, V. and Vanderplas, J. and Passos, A. and
-         Cournapeau, D. and Brucher, M. and Perrot, M. and Duchesnay, E.},
- journal={Journal of Machine Learning Research},
- volume={12},
- pages={2825--2830},
- year={2011}
+@Article{sk-learn,
+     title={Scikit-learn: Machine Learning in {P}ython},
+     author={Pedregosa, F. and Varoquaux, G. and Gramfort, A. and Michel, V.
+             and Thirion, B. and Grisel, O. and Blondel, M. and Prettenhofer, P.
+             and Weiss, R. and Dubourg, V. and Vanderplas, J. and Passos, A. and
+             Cournapeau, D. and Brucher, M. and Perrot, M. and Duchesnay, E.},
+     journal={Journal of Machine Learning Research},
+     volume={12},
+     pages={2825--2830},
+     year={2011}
 }
 
 @InCollection{knitr,
@@ -26,4 +26,32 @@ @InCollection{knitr
     publisher = {Chapman and Hall/CRC},
     year = {2014},
     note = {ISBN 978-1466561595},
-    url = {http://www.crcpress.com/product/isbn/9781466561595},}
+    url = {http://www.crcpress.com/product/isbn/9781466561595},
+}
+
+    
+@Manual{docopt,
+    title = {docopt: Command-Line Interface Specification Language},
+    author = {Edwin {de Jonge}},
+    year = {2018},
+    note = {R package version 0.6.1},
+    url = {https://CRAN.R-project.org/package=docopt},
+}
+
+@Manual{kableExtra,
+    title = {kableExtra: Construct Complex Table with 'kable' and Pipe Syntax},
+    author = {Hao Zhu},
+    year = {2020},
+    note = {R package version 1.3.1},
+    url = {https://CRAN.R-project.org/package=kableExtra},
+}
+
+  
+@misc{Dua:2019 ,
+    author = "Dua, Dheeru and Graff, Casey",
+    year = "2017",
+    title = "{UCI} Machine Learning Repository",
+    url = "http://archive.ics.uci.edu/ml",
+    institution = "University of California, Irvine, School of Information and Computer Sciences" 
+}
+