add disease.sh reference

references.bib

@@ -34,6 +34,16 @@
   number = {10}
 }
 
+@misc{disease.sh2021,
+  title = {Data from {{John Hopkins University}} ({{JHUCSSE}})},
+  author = {{disease.sh}},
+  year = {2021},
+  url = {https://disease.sh/},
+  urldate = {2021-03-31},
+  abstract = {An open API for disease-related statistics. No signup required. 	Over 45,000,000,000+ Requests \& 50 TB of Data Served to Date!},
+  journal = {disease.sh - Open Disease Data}
+}
+
 @misc{dorling2020,
   title = {Covid19 | {{SLOWDOWN}}},
   author = {Dorling, Danny},
@@ -61,7 +71,7 @@
   month = apr,
   publisher = {{Dezeen}},
   url = {https://www.youtube.com/watch?v=AD6khyFbBcQ},
-  keywords = {covid-19}
+  keywords = {covid-19,operational loops of covid-19}
 }
 
 @article{mattern2020,