?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Adissertation&rft.aulast=Halimah&rft.au=Halimah%2C+Halimah&rft.aufirst=Halimah&rft.inst=Universitas+Negeri+Padang&rft.date=February+2018&rft.degree=Bachelor%2FTugas+Akhir&rft.title=Analisa+Kekuatan+Pillar+pada+Rencana+Penambangan+Lubang+Utama+THC-02+CV.+Tahiti+Coal%2C+Talawi%2C+Sawahlunto.