Key points are not available for this paper at this time.
Mike Walker, Sigfus Johnsen, Sune Olander Rasmussen, Jørgen-Peder Steffensen, Trevor Popp, Philip Gibbard, Wim Hoek, John Lowe, John Andrews, Svante Björck, Les Cwynar, Konrad Hughen, Peter Kershaw, Bernd Kromer, Thomas Litt, David J. Lowe, Takeshi Nakagawa, Rewi Newnham, Jakob Schwander. Episodes 2008;31:264-7. https://doi.org/10.18814/epiiugs/2008/v31i2/016
Walker et al. (Sun,) studied this question.