Since there is no publication associated with this plugin, it is hard tracking where it is used. However people wrote me and helped building the following list. The Directionality plugin has been used at least in the following publications:
* Deravi, Leila F., Nina R. Sinatra, Christophe O. Chantre, Alexander P. Nesmith, Hongyan Yuan, Sahm K. Deravi, Josue A. Goss et al. [http://diseasebiophysics.seas.harvard.edu/wp-content/uploads/2017/01/pub_93.pdf "Design and Fabrication of Fibrous Nanomaterials Using Pull Spinning."] Macromolecular Materials and Engineering 302, no. 3 (2017).