Circuit designs for transponding acoustic tags are available in:

• Mitson, R.B. & Storeton West, T.J. (1971). A transponding acoustic fish tag. Radio Electron. Eng., 41, 483-489.
  
  
• Bagley, P.M. (1992). A code-activated transponder for the individual identification and tracking of deep-sea fish. Pages111-119 in Priede, I.G., and Swift, S.M. (eds.), Wildlife Telemetry, Ellis Horwood, New York.
  
  
• Bagley, P.M., Bradley, S., Collins, M.A., Priede, I.G. & Gray, P. (2000). Miniature acoustic code activated transponder for tracking fish at abyssal depths using delayed activation to overcome reverberation. Pages 13-19 in Moore, A., and Russell, I., Advances in Fish Telemetry, Proceedings of the Third Conference on Fish Telemetry in Europe, Norwich, England, 20-25 June 1999, CEFAS Lowestoft.