?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Adissertation&rft.aulast=Purnama&rft.au=Purnama%2C+Vera&rft.aufirst=Vera&rft.inst=Universitas+Negeri+Padang&rft.degree=Bachelor%2FSkripsi&rft.date=2018&rft.title=Biosorpsi+Ion+Logam+Berat+Kromium+(Cr6%2B)+Menggunakan+Biomassa+Alga+Hijau+(Spirogyra+setiformis)