Application of the large sieve to the solution of additive problems of mixed type

A variant of the large-sieve: method, using a combination of results obtained by Lavrik, Montgomery, and Eombieri, is employed to derive asymptotic properties of the number of solutions of the equation $N\mathfrak p+N\mathfrak a=n$ where $\mathfrak p$ is a prime ideal of some ideal class of a field $K$ of degree $n\le4$, and $\mathfrak a$ is a prime ideal of a class of an imaginary quadratic field.