Phillip Helbig, J. F. Macias-Perez, R. Quast, A. Wilkinson & R. D. Davies
"λ₀ and Ω₀ from Lensing Statistics and Other Methods: Is There a Conflict?"*
in Gravitational Lensing: Recent Progress and Future Goals (ADS: 2001ASPC..237.....B)
T. G. Brainerd & C. S. Kochanek (eds.)
San Francisco: Astronomical Society of the Pacific: PASP conference series No. 237, pp. 145–146 (2001)
ISBN 1-58381-074-9
ADS: 2001ASPC..237..145H | Google Scholar