Radiological and gamma-ray shielding parameters of cement raw materials samples used in Yemen Emran Eisa Saleh, Anwar Khadher Mohammed and Soad Abed Elmonem El-Fiki Eur. Phys. J. Plus, 136 8 (2021) 890 Published online: 30 August 2021 DOI: 10.1140/epjp/s13360-021-01885-z