1. J.Gruszczak
Discrete Spectrum of the Deficit Angle and the Differential Structure of a Cosmic String
Int J Theor Phys, vol. 47, pp. 2911-2923 (2008).

2. J.Gruszczak, M.Heller
Differential Structure of Space-Time and its Prolongations to Singular Boundary
Int J Theor Phys, vol. 32, pp. 625-648 (1993).

3. J. Gruszczak, M. Heller, Z. Pogoda
Cauchy Boundaries and b-Incompleteness of Space Times
Int J Theor Phys, vol. 30, pp. 555-565 (1991).

4. J. Gruszczak
Cauchy Boundaries of Space- Times
Int J Theor Phys, vol. 29, pp. 37-43 (1990).

5. J. Gruszczak, M. Heller and P. Muitarzynski
Physics With and Without the Equivalence Principle
Foundations of Physics, vol. 19, pp. 607-618 (1989).

6. J. Gruszczak, M. Heller and P. Multtarzynski
A Generalization of Manifolds as Space-Time Model
Journal of Mathematical Physics, vol. 29, pp. 2576-2580 (1988).

7. J.Gruszczak, M. Heller
Singularities in stochastically Predictable Universe
Physics Letters A, vol. 106, pp. 13-16 (1984).

8. J. Gruszczak, M. Heller, M. Szydlowski
The Universe as a Stochastic Process
Physics Letters A, vol. 100, pp. 82-84 (1982).

9. J. Gruszczak
Two-soliton solution of the Ernst Equation
Journal of Physics A, vol. 14, pp. 3247-3251 (1981).