Niwa, Yoshiji. <br/><br/>
Researches on vibration characteristics of hollow gravity d-ams / by Yoshiji Niwa, Motohiro Hatanaka and Shigeomi Samuk-awa. 

 - Kyoto, Japón : Kyoto University, Engineering Research Institute 
 - [13] p. 
 - Report; No. 46 .