Hayakawa, M., Y. Tanaka, K. Ohta, and T. Okada. “Absolute Intensity of Daytime Whistlers at Low and Middle Latitudes and Its Latitudinal Variation”. Journal of Geophysics 59, no. 1 (February 27, 1986): 67-72. Accessed October 12, 2025. https://journal.geophysicsjournal.com/JofG/article/view/230.