In Germany, the service was announced in October, 1979 according to an article in Computerwoche dated 1979-10-19. https://www.computerwoche.de/a/virtual-storage-personal-computing-vspc-mit-benutzersprache-as-neuer-dfv-service-der-ibm-rechenzentren,1194110
Leavitt, Don (1976-01-12). "VSPC Makes 370 'More Approachable'". Computerworld. Vol. 10, no. 2. pp. 1–2. Retrieved 2025-04-05. https://archive.org/details/computerworld1011unse_02/mode/2up?q=%22virtual+storage+personal+computing%22
Carlyle, R. Emmett (1984-10-15). "VSPC Users Lose Out". Datamation. pp. 46–49. Retrieved 2025-04-05. https://archive.org/details/bitsavers_datamation_44192572/page/n47/mode/2up