RT Article T1 Ecological influences on state police district activity JF The Police journal VO 83 IS 4 SP 305 OP 323 A1 Johnson, Richard Ronald 1937- A2 Billings, Ashley N. LA English YR 2010 UL https://krimdok.uni-tuebingen.de/Record/191252581X DO 10.1350/pojo.2010.83.4.503