Mulder, H.M., Julius Petersen’s theory of regular graphs, Discrete Mathematics 100 (1992) 157-17s. In 1891 the Danish mathematician Julius Petersen (1839-1910) published a paper on the factorization of regular graphs. This was the first paper in the history of mathematics to contain fundamental results explicitly in graph theory. In this report Petersen’s results are analysed and their developm...

It has been over 180 years since the first pre-school education institution was established in 1839. Over years, theory and practice of preschool have created, taking into account Polish social economic needs, marking good bad times education.