Here is another interresting article from July 1910. Macedonian is mentioned as a separate race in Turkey in Europe, Bulgaria and Greece, used by the United States Bureau of Immigration since 1899.
The article is called “The Economic Investigations of the United States Immigration Commission” by W. Jett Lauck, published in “The Journal of Political Economy”, Vol. 18, No. 7, (Jul., 1910), pp. 525-549. This is from page 527.