• [1] A. Cohn, Über die Anzahl der Wurzeln einer algebraischen Gleichung in einem Kreise, Math. Z. 14 (1922), no. 1, 110–148 (German). MR 1544543, https://doi.org/10.1007/BF01215894
• [2] Morris Marden, The Geometry of the Zeros of a Polynomial in a Complex Variable, Mathematical Surveys, No. 3, American Mathematical Society, New York, N. Y., 1949. MR 0031114
• [3] J. L. Walsh, The Location of Critical Points of Analytic and Harmonic Functions, American Mathematical Society Colloquium Publications, Vol. 34, American Mathematical Society, New York, N. Y., 1950. MR 0037350

Bibliography

[1]

A. Cohn, Über die Anzahl der Wurzeln einer Algebraischen Gleichung in einer Kreise, Math. Zeit. vol. 14 (1922) pp. 110-148. MR 1544543

[2]

M. Marden, The geometry of the zeros of a polynomial in a complex variable, Mathematical Surveys, no. 3, New York, American Mathematical Society, 1949; see p. 150. MR 0031114 (11:101i)

[3]

J. L. Walsh, Location of the critical points, Amer. Math. Soc. Colloquium Publications, vol. 34, 1950, pp. 52-55. MR 0037350 (12:249d)