additive measures in its range of applicability. . The paper Some recent developments of the theory of boundary value problems for linear partial differential equations details Fichera's approach to a general theory of boundary value problems for linear partial differential equations through a theorem similar in spirit to the Lax–Milgram theorem: as an application, the general existence and uniqueness theorems of previous paper are proved dropping the hypothesis of self-adjointness of the linear partial differential operators considered. . . This is the first paper on the theory of partial differential equations of non-positive characteristics: the Fichera's function is introduced and its applications to the boundary value problems for this class of operators is detailed. Also the well posedness of the problem is considered. . This is an epoch-making paper in the theory of CR-functions, where the Dirichlet problem for analytic functions of several complex variables is solved for general data. . "Linear spaces of –measures and differential forms" (English translation of the title) is perhaps the most important contribution of Gaetano Fichera to the theory of exterior differential forms: he introduces the –measures and shows that, despite being less general than currents and thus being easier to work with, they can be used to prove all the most important results of the theory. . A paper about the boundary value problem for partial differential equations of non-positive characteristics, where the Fichera's function is introduced and its application are described. . In this a work, an abstract theory of harmonic forms in Hilbert spaces is presented, and a proof of Hodge theorem is given. . This is the article where the now called "Fichera maximum principle" is proved. . A research announcement describing briefly (and without proofs) Gaetano Fichera's solution to the Signorini problem. . An ample memoir containing the detailed proofs of existence and uniqueness theorem for the Signorini problem, translated in the English language as . . In this paper Gaetano Fichera proves a semicontinuity theorem for functionals depending on a general linear operator, not necessarily being a partial differential operator. , . The encyclopedic entry written by Fichera on existence problems in linear elasticity for the Handbuch der Physik on invitation by Clifford Truesdell. , . The encyclopedic entry written by Fichera on problems with unilateral constraints (the class of boundary value problems the Signorini problem belongs to) for the Handbuch der Physik on invitation by Clifford Truesdell.