Publication Type:
Journal ArticleSource:
Uspekhi Mat. Nauk, Volume 45, p.183–184 (1990)URL:
http://dx.doi.org/10.1070/RM1990v045n05ABEH002673Notes:
<p>Warning: the main theorem of this paper was shown by Carlos Simpson to be false.</p>
<p>Warning: the main theorem of this paper was shown by Carlos Simpson to be false.</p>