@phdthesis{UNY29047,
            year = {2015},
          school = {Universitas Negeri Yogyakarta},
          author = {Kholis Nurhanafi},
           title = {Karakteristik Mikrotremor di Permukaan Sungai Bawah Tanah Bribin, Kawasan Karst Gunung Sewu, Berdasarkan Analisis Spektrum, Horizontal to Vertical Spectral Ratio (HVSR), dan Time Frequency Analysis(TFA)},
           month = {November},
             url = {http://eprints.uny.ac.id/29047/}
}