https://britishbirds.co.uk/sites/default/files/V55_N12_P584-589_A071_0.pdf
This is old archive article by the head warden at Minsmere, Bert Axell from 1975
Regards,
Ian.
https://britishbirds.co.uk/sites/default/files/2017_V110_N08_435-455_Minsmere.pdf
This is an article by the manager at Minsmere and published in 2017(Adam Rowlands): Great Bird Reserve: RSPB Minsmere.