Generalized Feynman-Hellmann theorem for ensemble average values

Generalized Hellmann-Feynman Theorem for Ensemble Average Expressed in the Formalism of Pure State Expectation

A note on the generalized Hellmann–Feynman theorem

Generalization of the Hellmann–Feynman theorem

Modified Hellmann Feynman Theorem

On the Hellmann-Feynman theorem in statistical mechanics

The extended Hellmann-Feynman theorem revisited