A Simple Theoretical Model for Ring and Nanotube Radial Breathing Mode
ZHOU Tao, XU Can, ZHANG Xiao-Fang, CHENG Chuan, CHEN Liang, XU Ying
Acta Phys. -Chim. Sin. . 2008, (09): 1579 -1583 .  DOI: 10.1016/S1872-1508(08)60065-0