Adding references to README

docs/open_knowledge_graph_on_clinical_trials/README.md

@@ -34,13 +34,16 @@ Below is a brief specification
 # References
 
 ## Apache Jena
+- [Download](https://jena.apache.org/download/index.cgi)
+- 
 - [Read](https://jena.apache.org/documentation/io/rdf-input.html) RDF files
 - [Write](https://jena.apache.org/documentation/io/rdf-output.html) RDF files
 - [Querying](https://jena.apache.org/tutorials/rdf_api.html#ch-Querying-a-Model) a model
 - [SparQL](https://jena.apache.org/tutorials/sparql_query1.html)
 - index RDF files
 - [query](https://towardsdatascience.com/extract-and-query-knowledge-graphs-using-apache-jena-sparql-engine-5c66648797a4) RDF files using indexes
 - count triples [query](https://stackoverflow.com/a/51289880/294552)
+- Execute SparQL query [programmatically](https://github.com/apache/jena/blob/main/jena-examples/src/main/java/arq/examples/ExProg1.java)
 
 ## Java
 - Configure Java [heap](https://stackoverflow.com/a/47388044/294552) size and if needed [stack](https://stackoverflow.com/a/44253141/294552) size.
@@ -53,6 +56,7 @@ Below is a brief specification
 - Other older relevant links on Java and Entrez
   - [download-pubmed-abstracts-in-java](https://stackoverflow.com/questions/5410151/download-pubmed-abstracts-in-java)
   - Github repo : [pubmed_ws_client](https://github.com/renaud/pubmed_ws_client)
+- Read file into a [string](https://howtodoinjava.com/java/io/java-read-file-to-string-examples/)
 
 ## Linux commands
 - Check if string exists in file in [bash](https://stackoverflow.com/a/4749368/294552)