Journal article (1999) - S Otte (author), J.G. Kuenen (author), LP Nielsen (author), HW Paerl (author), J Zopfi (author), HN Schulz (author), A Teske (author), B Strotmann (author), VA Gallardo (author), BB Jorgensen (author)

Journal article (1999) - HN Schulz (author), W Bohringer (author), F Ousmanov (author), PGW Waller (author)