1. Design of testable random bit generators;Bucci,2005
2. High-speed true random number generation with logic gates only;Dichtl,2007
3. Fast digital TRNG based on metastable ring oscillator;Vasyltsov,2008
4. A Proposal for: Funtionality Classes and Evaluation Methodology for True (Physical) Random Number Generatorshttps://www.bsi.bund.de/SharedDocs/Downloads/DE/BSI/Zertifizierung/Interpretationen/AIS_31_Functionality_classes_evaluation_methodology_for_true_RNG_e.pdf?__blob=publicationFile&v=1