Asymptotic behavior of entire functions wich zeros are located at a certain angle

The following issues will be discussed.
1. Regular growth of entire functions of exponential type with zeros that have zero condensation index.
2. The problem of the greatest lower bound of types of all possible entire functions of order $\rho\in(0,1)$ which zeros lie in a fixed angle and have predetermined upper and lower $\rho$-density.
3. Krein problem of expanding of the reciprocal of an entire function in a series of simple fractions of a special structure (M. G. Krein's, 1947).