<h1>Keightley, Willard Otis</h1>
<h2>Article from <a href="https://authors.library.caltech.edu">CaltechAUTHORS</a></h2>
<ul>
<li>Hudson, D. E. and Keightley, W. O., el al. (1964) <a href="https://resolver.caltech.edu/CaltechAUTHORS:20140801-111018702">A new method for the measurement of the natural periods of buildings</a>; Bulletin of the Seismological Society of America; Vol. 54; No. 1; 233-241</li>
</ul>