APA: 
Hill, Carol A., Buecher, Robert H. (1992). Nitrocalcite in Kartchner caverns, Kartchner caverns State park, Arizona, USA. 
Acta carsologica, letnik 21, str.151-156. 
URN:NBN:SI:DOC-OSXGQKZD from http://www.dlib.si
 
                           MLA: 
Hill, Carol A., Buecher, Robert H.. "Nitrocalcite in Kartchner caverns, Kartchner caverns State park, Arizona, USA." 
Acta carsologica letnik 21 (1992) str.151-156.
<http://www.dlib.si/?URN=URN:NBN:SI:DOC-OSXGQKZD>