DiTrapani J, Rockwood N, Jeon M. Explanatory IRT analysis using the SPIRT macro in SPSS. TQMP. 2018;14(2):81-98. doi: 10.20982/tqmp.14.2.p081
Vickers AD, Rotherham ID, Rose J. Vegetation succession and colonisation rates at the forest edge under different environmental conditions. Ann Appl Biol. 2000;58:1-8.
Vickers AD, Rotherham ID. The response of Bluebell (Hyacinthoides non-scripta) to seasonal differences between years and woodland management. Ann Appl Biol. 2000;58:351-6.