article published in 1992

scientific article published in June 2009

scientific article published in April 1989

scientific article published in May 1991

scientific article published in September 2008

scientific article published in October 1995

scientific article published in May 2004

scientific article published in August 2000

scientific article published in July 2013

scientific article published in February 1992

scientific article published in October 1993

scientific article published in November 2004

scientific article published in September 2015

scientific article published in March 2003

scientific article published in October 2003

scientific article published in May 2004

scientific article published in September 1996

scientific article published in February 1998