The sources

Benz Patent Motor Car: The First Automobile, 1885-1886

Mercedes-Benz Group · Company History · 1885

Bertha Benz’s August 1888 Mannheim to Pforzheim drive with Eugen, fifteen, and Richard, fourteen; the ligroin from the Wiesloch pharmacy; the hatpin.

Cited in

Mercedes-Benz Group. 'Benz Patent Motor Car: The First Automobile, 1885-1886.' Company History. (Bertha Benz's August 1888 Mannheim to Pforzheim drive with Eugen, fifteen, and Richard, fourteen; the ligroin from the Wiesloch pharmacy; the hatpin.)