The Monotonicity Theorem, Cauchy's Interlace Theorem, and the Courant- Fischer Theorem
Yasuhiko Ikebe, Toshiyuki Inagaki, Sadaaki Miyamoto · American Mathematical Monthly · 1987
Yasuhiko Ikebe, Toshiyuki Inagaki, Sadaaki Miyamoto, The Monotonicity Theorem, Cauchy's Interlace Theorem, and the Courant- Fischer Theorem, The American Mathematical Monthly, Vol. 94, No. 4 (Apr., 1987), pp. 352-354