the extragalactic distance scale key project. III. The discovery of cepheids and a new distance to M101 using the hubble space telescope

DD Kelson, GD Illingworth, WF Freedman, JA Graham, R Hill, BF Madore, A Saha, PB Stetson, RC Kennicutt, JR Mould, SM Hughes, L Ferrarese, R Phelps, A Turner, KH Cook, H Ford, JG Hoessel, J Huchra