■Preface
As the Editor-in-Chief of Physics Education in University
Jin Nakamura......687

■Topics
Evidence for Nano-Hz Gravitational-Wave Background by Pulsar Timing Array
Keitaro Takahashi......690

■Overview Articles
Three Body Problem―Its Past and Present
Hideki Asada......692

■Researches
Can Periodicity of Crystals Coexist with a Glasslike Network?
Yui Ishii and Shigeo Mori......700
Magnetization Reversal by Electric Field in Cobalt-Substituted Bismuth Ferrite Thin Film
Kei Shigematsu, Keisuke Shimizu, Hajime Hojo, and Masaki Azuma......706

■The Path to History
X-ray Laboratory in the de Broglie Castle and Matter Waves
Chieko Kojima......711

■La Toccata
The 75th Anniversary of "Soryushiron Kenkyu"
Takeshi Morita and Michiji Konuma......715

■JPSJ Selected Papers in the Latest Issue......718

■PTEP Selected Papers in the Latest Issue......719

■Book Reviews......721