Šatinskas R., Pleskačiauskas A., Stabinytė D., and Vaitkevičius H. “Influence of Relative Luminance and Angle Between Movement Directions of Two Moving Stimuli on Direction Detecting”. Psichologija, Vol. 24, Jan. 2001, pp. 58-68, doi:10.15388/Psichol.2001..4410.