Analysis of information sources in references of the Wikipedia article "การเตือนภัยแผ่นดินไหวล่วงหน้า (ประเทศญี่ปุ่น)" in Thai language version.
Seismometers installed at 4,235 locations are working throughout Japan as of 1 April 2010 (per right side figure on page 1)
Seismometers installed at 4,235 locations are working throughout Japan as of 1 April 2010 (per right side figure on page 1)