Rodgers-Lee, Donna ORCID: 0000-0002-0100-1297, Taylor, A. M., Downes, Turlough ORCID: 0000-0002-7639-5446 and Ray, Tom ORCID: 0000-0002-2110-1068 (2019) Stellar cosmic rays as an important source of ionization in protoplanetary discs: a disc mass-dependent process. Monthly Notices Of The Royal Astronomical Society, 491 (4). pp. 4742-4751. ISSN 0035-8711