Adomako K, Hagan J K and Olympio O S 2010:
Egg production performance of first and second filial generation naked neck (NaNa, Nana) and normal feathered (nana) birds of a cross between indigenous naked neck (NaNa, Nana) males and exotic commercial females (nana).
Livestock Research for Rural Development. Volume 22, Article #223.
, from http://www.lrrd.org/lrrd22/12/adom22223.htm