the extragalactic distance scale key project. III. The discovery of cepheids and a new distance to M101 using the hubble space telescope
Journal article published in 1996 by
Kelson,
G. D. Illingworth,
W. F. Freedman,
J. A. Graham,
R. Hill,
B. F. Madore,
A. Saha 
,
P. B. Stetson,
R. C. Kennicutt,
Mould,
S. M. Hughes,
L. Ferrarese,
R. Phelps,
A. Turner,
K. H. Cook
and other authors.
,
P. B. Stetson,
R. C. Kennicutt,
Mould,
S. M. Hughes,
L. Ferrarese,
R. Phelps,
A. Turner,
K. H. Cook
and other authors.
