Abstract
In the version of this Correspondence originally published, the wrong paper was given for ref. 1; instead of ‘Shields, G. A. Nature 273, 519–520 (1978)‘ it should have been ‘Shields, G. A. Nature 272, 706–708 (1978)’. This has now been corrected.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have