References http://www.shaltzfarm.com/shetcolgen.html http://dorper.org/Journal/DorperJournal2.pdf http://www.icelandicsheep.com/genetics.html http://everranch.com/Farm/Sheep/Gotlands/P02GotlandTOC.htm http://everranch.com/Farm/Sheep/Gotlands/P07GotlandColor.htm Fat Tailed Color Genetics Goat Color Genetics