RT Book, Whole DB /z-wcorg/ DS http://worldcat.org ID 10122252 LA English T1 International Halley watch amateur observers' manual for scientific comet studies A1 Edberg, Stephen J. PB Enslow Publishers ; Sky Pub. Corp. PP Hillside, NJ; Cambridge, Mass. YR 1983 SN 0894901028 : 9780894901027