2021 Volume 97 Issue 4 Pages 210
In this paper, the following should be corrected:
(page 121, Fig. 1)
Insert “This figure is reproduced from Iwai96) with some modifications.” at the end of the legend of Fig. 1.
(page 123, Fig. 2)
Insert “This figure is reproduced from Iwai96) with some modifications.” at the end of the legend of Fig. 2.