Wisdom's Wittgenstein
N. Milkov, in: A.H. Khani , G. Kemp  (Eds.), Wittgenstein and Other Philosophers: His Influence on Historical and Contemporary Analytic Philosophers, 2 Vol., Volume II, 1st ed., Routledge, London, n.d.

Frege, Gottlob (1848–1925)
N. Milkov, in: C. Adair-Toteff (Ed.), Bloomsbury Encyclopedia of Philosophers, 1st ed., Bloomsbury, London, 2020.