  Following some ideas in the Landau book, some corrections about errors in the
old literature on scalar gravitational waves are given and discussed. Even if
such errors can be considered not important from the point of view of
observations, because they do not alter the interferometric response function
for scalar gravitational waves, the presented analysis is due and very
important for a sake of completeness and for a better understanding of the
linearized theory of Scalar-Tensor Gravity
