14-Apr-69, V.M. Buchstaber.
21-Apr-69, V.M. Buchstaber.
23-Oct-72, V.M. Buchstaber.
30-Oct-72, V.M. Buchstaber.
13-Nov-72, V.M. Buchstaber.
20-Nov-72, V.M. Buchstaber.
12-Feb-73, V.M. Buchstaber.
26-Feb-73, V.M. Buchstaber.
12-Mar-73, V.M. Buchstaber.
20-Mar-78, V.M. Buchstaber.