Template:Ettl, 1978
- Ettl, H. 1978. Über Hydrianum viride (Characiaceae, Chlorophyceae), seine Fortpflanzung und Taxonomie [On Hydrianum viride (Characiaceae, Chlorophyceae), Its Reproduction and Taxonomy]. Plant Systematics and Evolution 129(3): 209–219. DOI: 10.1007/BF00990761, JSTOR