@unpublished{ITNYREPOID3791,
          author = {Listiyani Retno Astuti},
           title = {Bukti review korespondensi: Stable isotopes changes in groundwater: case study in Mudal and Clapar springs,  Progo},
       publisher = {ITNY},
             url = {https://repository.itny.ac.id/id/eprint/3791/}
}