RT Article T1 Grade-level distinctions in student threats of violence JF Journal of school violence VO 19 IS 3 SP 323 OP 335 A1 Burnette, Anna G. A1 Cornell, Dewey G. A1 Konold, Timothy A2 Cornell, Dewey G. A2 Konold, Timothy LA English YR 2020 UL https://krimdok.uni-tuebingen.de/Record/1912568810 DO 10.1080/15388220.2019.1694031