But, I just ran into two annotated references on the wobbling of the Earth, which I would like to read if I ever get the time. They're from the 2nd edition of Goldstein's Classical Mechanics:
One of the most fascinating applications of the dynamics of rigid bodies is to the phenomena of the rotating earth - although the first step is to realize to what an extent the earth and its appurtenances deviate from a rigid body. The treatise of Munk and Macdonald provides a well-written, lucid introduction to these geophysical applications, which range from continental drift through ancient historical records of eclipses to questions of earthquake excitation of Chandler wobble. Unfortunately - or is it happily? - the treatment cannot be considered as definitive because the field is undergoing intense development and significant advances have been made since the 1960 publication date. But any study of the features of the Earth's rotation would do well to start with Munk and Macdonald.
Chapter 2 provides a compact discussion of such topics as precession fo the equinoxes and the Chandler wobble, with references to the modern literature.
Ciao... for now!