APA: 
Mais, Karl (1999). Roofless Caves, a polygenetic status of cave development with special references to cave regions in the Eastern Calcareous Alps in Salzburg and Central Alps, Austria. 
Acta carsologica, letnik 28, številka 2, str. 145-158. 
URN:NBN:SI:doc-N3IN2BX8 from http://www.dlib.si
 
                           MLA: 
Mais, Karl. "Roofless Caves, a polygenetic status of cave development with special references to cave regions in the Eastern Calcareous Alps in Salzburg and Central Alps, Austria." 
Acta carsologica letnik 28. številka 2 (1999) str. 145-158.
<http://www.dlib.si/?URN=URN:NBN:SI:doc-N3IN2BX8>