good stuff :)
some refs:
http://iopscience.iop.org/article/10.1088/0004-637X/767/1/92/pdf http://arxiv.org/pdf/1207.6105v2.pdf
good stuff :)
some refs:
http://iopscience.iop.org/article/10.1088/0004-637X/767/1/92/pdf http://arxiv.org/pdf/1207.6105v2.pdf