Added reference to code branch

Author: AlexGustafsson

README.md

@@ -6,6 +6,8 @@ This project evaluates the relative performance of various algorithms for intege
 
 The paper was written on a public instance of [ShareLatex](The easy to use, online, collaborative LaTeX editor) and built on a private instance of the same service. ShareLatex makes it easy to collaboratively write a paper using LaTeX whilst still being completely free and partly open source.
 
+The code is available in the default branch [cocalc](https://github.com/AlexGustafsson/practical-factorization-comparison/).
+
 See also: [Course Notes](https://github.com/CourseNotesBTH) for BTH courses and code and examples for [Programming Courses at BTH](https://github.com/ProgrammingCoursesBTH).
 
 # Quickstart