@article{bak87,
        title = {Self-organized criticality: An explanation of the 1/f noise},
        author = {Per Bak and Chao Tang and Kurt Wiesenfeld},
        journal = {Phys. Rev. Lett.},
        month = {Jul},
        number = 4,
        pages = {381--384},
        publisher = {American Physical Society},
        volume = 59,
        year = 1987,
        numpages = {3},
	doi = {10.1103/PhysRevLett.59.381},
	description = {granular soc},
	biburl = {http://www.bibsonomy.org/bibtex/2ab2978a98bc36e0e0fcc5fe0231d0249/alpe},
	keywords = {imported}
}