Add references.bib with article citation

Author: eeholmes

book/references.bib

@@ -0,0 +1,12 @@
+@article {Huppenkothen2018,
+author = {Huppenkothen, Daniela and Arendt, Anthony and Hogg, David W. and Ram, Karthik and VanderPlas, Jacob T. and Rokem, Ariel},
+title = {Hack weeks as a model for data science education and collaboration},
+volume = {115},
+number = {36},
+pages = {8872--8877},
+year = {2018},
+doi = {10.1073/pnas.1717196115},
+publisher = {National Academy of Sciences},
+issn = {0027-8424},
+journal = {Proceedings of the National Academy of Sciences}
+}