Horn, B. K. P., D. Marr, J. Hollerbach, G. J. Sussman, P. H. Winston, R. Davis, and M. L. Minsky. “Research in Progress at the Massachusetts Institute of Technology Artificial Intelligence Laboratory”. AI Magazine, vol. 1, no. 1, July 2017, p. 21, doi:10.1609/aimag.v1i1.87.