Furniss, A., Williams, D., Danforth, C., Fumagalli, M., Prochaska, J., Primack, J., …Neely, W. (2013). The Firm Redshift Lower Limit of the Most Distant TeV-detected Blazar PKS 1424+240. Astrophysical Journal Letters, 768(2), Article L31. https://doi.org/10.1088/2041-8205/768/2/l31