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Submitted on: 23 June 2020.
Revised on: 01 September 2020.
Accepted on: 22 September 2020.
___________________Erwerbs-Obstbau---SPRINGER
Submitted on: 07 August 2000.
Revised on: 24 September 2000.
Accepted on: 04 November 2000.
___________________Erwerbs-Obstbau---SPRINGER
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