Makbul, Serdar, Zafer Türkmen, Kamil CoÅŸkunçelebi, and Osman BeyazoÄŸlu. 2010. “Morfometric Study on Scorzonera L. Taxa (Asteraceae) from Northeast Anatolia”. Acta Botanica Croatica 69 (2). https://www.abc.botanic.hr/index.php/abc/article/view/200.