@article{https://resolver.caltech.edu/CaltechAUTHORS:20140801-113026550, title = "Mode superposition in multi-degree of freedom systems using earthquake response spectrum data", journal = "Bulletin of the Seismological Society of America", url = "https://resolver.caltech.edu/CaltechAUTHORS:20140801-113026550", id = "record", issn = "0037-1106", volume = "52" } @other{https://resolver.caltech.edu/CaltechEERL:1961.EERL.1961.004, title = "Mode superposition methods applied to linear mechanical systems under earthquake type excitations", url = "https://resolver.caltech.edu/CaltechEERL:1961.EERL.1961.004", id = "record" }