de Kloet, RS; de Kloet SR (2005). "The evolution in the spindlin gene in birds: Sequence Evaluation of an intron in the spindlin W and Z gene reveals four big divisions from the Psittaciformes". Cockatiels are modest https://haleemafktf043324.bloggactif.com/31045644/the-definitive-guide-to-african-grey-parots-for-sale