http://www.woodducksociety.com/WDHouse.pdf
http://www.woodducksociety.com/newest%2 ... 0guard.pdf
No ladders and no trees article:
http://www.prairiepotholeday.com/pdf/No%20Ladders.pdf
Best practices method for Woodie Boxes;
http://www.woodducksociety.com/bestpractices.htm