Yu.I. Portnyagin
发表
Farzad Kamalabadi,
Jeffrey M. Forbes,
J. Forbes,
1997
.
Ch. Jacobi,
Werner Singer,
W. Singer,
2001
.
Scott Edward Palo,
Jeffrey M. Forbes,
Yu.I. Portnyagin,
2000
.
Ch. Jacobi,
Peter Hoffmann,
Werner Singer,
1999
.
Jan Laštovička,
Thomas Ulich,
Gufran Beig,
2008
.
John W. MacDougall,
S. B. Malinga,
Ch. Jacobi,
2002
.
Antonina N. Fahrutdinova,
Jeffrey M. Forbes,
Ch. Jacobi,
2009
.