@article{article4e3d7447,
title   = {Retardation of homing pigeons ephemerides?},
author = {Schmidt-Koenig, K and Ranvaud, Ronald Dennis Paul Kenneth Clive and Ganzhorn, J U and Gasparotto, O C},
year = {1991},
doi = {10.1007/bf01221424},
journal   = {Naturwissenschaften}
}