M. Schindelegger, D. Einspigel, D. Salstein, J. Böhm:
"The global S1 tide in Earth's nutation";
Surveys in Geophysics, 37 (2016), Issue 3; 643 - 680.
http://dx.doi.org/10.1007/s10712-016-9365-3Electronic version of the publication:
http://link.springer.com/article/10.1007/s10712-016-9365-3