Characterization of Red Sandstone and Black Crust to Analyze Air Pollution Impacts on a Cultural Heritage Building: Red Fort, Delhi, India. - Kumar, Gaurav; Rusin, Lucia; Nagar, Pavan Kumar; Manjul, Sanjay Kumar; Back, Michele; Benedetti, Alvise; Gurjar, Bhola Ram; Ojha, Chandra Shekhar Prasad; Sharma, Mukesh; Balliana, Eleonora (Heritage (2571-9408), 2025)