Riekje, Ruud en Roetje, from Dutch newspaper Utrechts Nieuwsblad (2/1/1960)
Hildur Eckardt is a Danish illustrator. Eckardt worked for the Børnehave magazine in the 1950s and is responsible for serials like 'Polla, Palli og Krunki' and most likely 'Tove, Tom og Svarteper' (PIB agency).