@article{al2006the,
author = {al., J.K. Adelman-McCarthy et and Gray, Jim and al., et.},
title = {The Fourth Data Release of the Sloan Digital Sky Survey},
year = {2006},
month = {January},
abstract = {This paper describes the fourth data release of the Sloan Digital Sky Survey (SDSS), including all survey-quality data taken through June 2004. The data release includes five-band photometric data for 180 million objects selected over 6670 deg^2, and 673,280 spectra of galaxies, quasars, and stars selected from 4783 deg^2 of that imaging data using the standard SDSS target selection algorithms. These numbers represent a roughly 25% increment over those of the Third Data Release. The Fourth Data Release also includes an additional 131,840 spectra of objects selected using a variety of alternative algorithms, to address scientific issues ranging from the kinematics of stars in the Milky Way thick disk to populations of faint galaxies and quasars.},
url = {http://approjects.co.za/?big=en-us/research/publication/the-fourth-data-release-of-the-sloan-digital-sky-survey/},
pages = {38-48},
journal = {Astrophysics},
volume = {162},
}