Trosper, Jaime «A Black Hole's Core Could be a Strange "Planck Star"» (en anglès). Interesting Engineering, 03-07-2021 [Consulta: 26 desembre 2021]. «In the most basic terms, Planck length is the smallest possible unit of measurement.»
thehindu.com
«Know the scientist: Max Planck» (en anglès). The Hindu, 18-02-2021 [Consulta: 26 desembre 2021]. «The discovery of Planck's constant enabled him [Max Planck] to define a new universal set of physical units such as the Planck length and the Planck mass.»
