Finally, one definitive paper on the sDNA software itself: when you next need to cite the software please use
Cooper, C.H.V., Chiaradia, A.J.F., 2020. sDNA: 3-d spatial network analysis for GIS, CAD, Command Line & Python. SoftwareX 12, 100525. https://doi.org/10.1016/j.softx.2020.100525
All published results should cite the software – please help us to help you, as demonstrating impact means we can put more work into sDNA in future. Although focused on sDNA Open, the above paper is suitable for all of the sDNA family including sDNA and sDNA+.