scientific article published in March 1991

scholarly article

scientific article published in Astronomy and Astrophysics

scientific article published in Astronomy and Astrophysics

scientific article published in Astronomy and Astrophysics

article published in 1997

scientific article published in Nature

scientific article published in Astronomy and Astrophysics

scientific article

scientific article

scientific article published in Astronomy and Astrophysics

scientific article published in Astronomy and Astrophysics

scientific article published in the Astrophysical Journal

scientific article published in Astronomy and Astrophysics