http://xmm.esac.esa.int/docs/documents/CAL-SRN-0215-1-0.ps.gz
http://xmm.esac.esa.int/docs/documents/CAL-SRN-0176-1-1.ps.gz
http://xmm.esac.esa.int/docs/documents/CAL-SRN-0143-1-0.ps.gz
http://xmm.esac.esa.int/docs/documents/CAL-SRN-0108-1-0.ps.gz
http://xmm.esac.esa.int/docs/documents/CAL-SRN-0071-1-0.ps.gz
http://xmm.esac.esa.int/docs/documents/CAL-SRN-0012-1-0.ps.gz