Martin R., Perrow; Schutten, J. Hans; Howes, John R.; Holzer, Tim; Madgwick, F. Jane; Jowitt, Adrian J.D. (1997). "Interactions between coot (Fulica atra) and submerged macrophytes: the role of birds in the restoration process". Hydrobiologia. 342/343: 241–255. doi:10.1023/A:1017007911190. S2CID8235224.
Martin R., Perrow; Schutten, J. Hans; Howes, John R.; Holzer, Tim; Madgwick, F. Jane; Jowitt, Adrian J.D. (1997). "Interactions between coot (Fulica atra) and submerged macrophytes: the role of birds in the restoration process". Hydrobiologia. 342/343: 241–255. doi:10.1023/A:1017007911190. S2CID8235224.