[1] Leibniz Univ Hannover, Max Planck Inst Gravitat phys, Albert Einstein Inst, Callinstr 38, D-30167 Hannover, Germany
[2] Univ Wisconsin, Ctr Gravitat Cosmol & Astrophys, Dept Phys, POB 413, Milwaukee, WI 53201 USA
[3] Newcastle Univ, Newcastle Upon Tyne NE1 7RU, Tyne & Wear, England
[4] Univ Toronto, Toronto, ON M5S 3H4, Canada
[5] Naval Res Lab, Space Sci Div, Washington, DC 20375 USA
[6] Eotvos Lorand Univ, Inst Phys & Astron, Pazmany Ps 1-A, H-1117 Budapest, Hungary
[7] Natl Radio Astron Observ, Cambridge, MA 22903 USA
[8] West Virginia Univ, Dept Phys & Astron, POB 6315, Morgantown, WV 26506 USA
[9] West Virginia Univ, Morgantown, VA 26505 USA
[10] Yale Univ, Dept Phys, New Haven, CT 06520 USA
[11] Ist Nazl Astrofis, Osservatorio Astron Cagliari, via Sci 5, I-09047 Selargius, CA, Italy
[12] Univ Virginia, Dept Astron, POB 400325, Charlottesville, VA 22904 USA
[13] Vanderbilt Univ, Nashville, TN 37235 USA
[14] Natl Acad Sci, Natl Res Council, Washington, DC 20001 USA
[15] Natl Radio Astron Observ, Cambridge, MA 87801 USA
[16] Johns Hopkins Univ, William H Miller III Dept Phys & Astron, 3400 N Charles St, Baltimore, MD 21218 USA
[17] Giant Army, 915A 17th Ave, Seattle, WA 98122 USA
[18] Lafayette Coll, Lafayette, LA 18042 USA