O'Brian, T.
, Parr, A.
and Early, E.
(1998),
Standard Reference Materials:Film step tablet standards of diffuse visual transmission density - SRM 1001 and SRM 1008, , National Institute of Standards and Technology, Gaithersburg, MD, [online], https://doi.org/10.6028/NIST.SP.260-135
(Accessed November 8, 2024)