  In this article, the problem of identifying the source term in transport
processes given by a complete parabolic equation is studied mathematically from
noisy measurements taken at an arbitrary fixed time. The problem is solved
analytically with Fourier techniques and it is shown that this solution is not
stable. Three single parameter families of regularization operators are
proposed to dealt with the instability of the solution. Each of them is
designed to compensate the factor that causes the instability of the inverse
operator. Moreover, a rule of choice for the regularization parameter is
included and a H\"older error bound type is obtained for each estimation.
Numerical examples of different characteristics are presented to demonstrate
the benefits of the proposed strategies.
