scholarly article in Sida, vol. 17 no. 1, 1996

scholarly article in Sida, vol. 9 no. 1, 1981

scholarly article in Sida, vol. 10 no. 2, 1983

scholarly article in Sida, vol. 10 no. 4, 1984

scholarly article in Sida, vol. 17 no. 4, 1997

scientific article published in 1994

scholarly article published in 1976

scientific article published in December 2007

scholarly article in Sida, vol. 13 no. 3, 1989

scholarly article in Sida, vol. 16 no. 3, 1995

scholarly article in Sida, vol. 12 no. 2, 1987

scholarly article in Sida, vol. 9 no. 3, 1982

scientific article published in 2009

scholarly article in Sida, vol. 10 no. 3, 1984

scholarly article in Sida, vol. 10 no. 3, 1984

scholarly article in Sida, vol. 12 no. 2, 1987

scientific article published in June 2012

scholarly article in Sida, vol. 15 no. 1, 1992

scientific article

scientific article published in 2007

scholarly article in Sida, vol. 14 no. 4, 1991

scientific article published in 2008

scholarly article in Sida, vol. 18 no. 2, 1998

scholarly article in Sida, vol. 17 no. 2, 1996

scholarly article in Sida, vol. 18 no. 4, 1999

scholarly article in Sida, vol. 10 no. 3, 1984

scholarly article published in 1980

scholarly article published in 1977

article published in 1988

scholarly article in Sida, vol. 13 no. 1, 1988

scientific article published on 9 December 1983

scientific article (publication date: May 2004)

scientific article published in 1977

scholarly article in Sida, vol. 21 no. 1, 2004

scholarly article in Sida, vol. 9 no. 2, 1981

scholarly article in Sida, vol. 16 no. 3, 1995

scholarly article in Sida, vol. 10 no. 2, 1983

scholarly article in Sida, vol. 14 no. 1, 1990

scientific article

scholarly article in Sida, vol. 9 no. 1, 1981

scholarly article in Sida, vol. 14 no. 2, 1990

scholarly article in Sida, vol. 15 no. 3, 1993

scientific article published in 1981

scholarly article in Sida, vol. 18 no. 1, 1998

scientific article published in 2013

scholarly article in Sida, vol. 11 no. 3, 1986