Forbes, J. M.
Portnyagin, Yu. I.
Makarov, N. A.
Palo, S. E.
Merzlyakov, E. G.
Zhang, X.
Article History
Received: 17 August 1998
Revised: 15 March 1999
Accepted: 16 June 1999
First Online: 26 June 2014
Free to read: This content has been made available to all.