Frege: Two Theses, Two Senses: Article by Carlo Penco discusses a vacillation by Frege in his account of the relation between thoughts and sentences. Penco discusses the attempts to resolve this uncertainty by Currie, Dummett and others before advancing his own account.
Gottlob Frege: Short biography from the Metaphysics Research Lab at Stanford.
Gottlob Frege: Biography from the MacTutor History of Mathematics archive.