Processed apple products workshop, June 2 - 3, 1992 / Editor Donald L. Downing . New York :  Cornell Univ. , 1992 . 25 s . [1, of that borrowed 0]

The World book encyclopedia of science. Volume 4, The Planet Earth . Chicago :  World Book Inc. , 1991 . 158 s . ISBN 0-7166-3226-8 . [1, of that borrowed 0]