Prototype of Instrumented Rock Bolt for Continuous Monitoring of Roof Fall Hazard in Deep Underground Mines. - Krzysztof Fulawka; Witold Pytel; Marcin Szumny; Piotr Mertuszka; Bogumila Palac-Walko; Philipp Hartlieb; Michel Jakic; Michael Nöger (Sensors, 2023)