Frege: Acknowledgement and Inference

https://www.philosophy.ox.ac.uk/people/susanne-bobzien

Frege's Proof of Referentiality

https://unifind.unisr.it/get/person/boccuni-francesca

Impersonal and Existential Judgments in Sigwart, Schuppe and Frege

https://www.pe.ruhr-uni-bochum.de/philosophie/i/metaphysics/team/rami.html.de

Judgement and the Sinn/Bedeutung Distinction

https://www.universiteitleiden.nl/en/staffmembers/maria-van-der-schaar

Is Its Logical System Well-Suited to the Project of Frege’s Grundgesetze?

https://crispinjwright.com/