by DeBra, D, Bencze, W J, Everitt, C W F, VandenBeukel, J, Kirschenbaum, J
Published in Classical and quantum gravity (19.11.2015)

by van den Beukel, Jilles, Wortel, Rinus
Published in Geophysical research letters (01.10.1987)

by Dougherty, H., Hegel, D., Kirschenbaum, J., Vanden Beukel, J., Reeve, W., Kasdin, J.
Published in Control engineering practice (01.08.1995)