Reference S1. Project development procedures manual: chapter 29 – landscape architecture: section 2 highway planting, wildflower planting

Reference S1. California Department of Transportation. 2016. Project development procedures manual: chapter 29 – landscape architecture: section 2 highway planting, wildflower planting. California Department of Transportation, CalTrans. (Editor Gary Birch). Sacramento, California: Division of Design, Chief Office of Standards and Procedures. Pages 29-12 to 29-39. also available at http://www.dot.ca.gov/hq/oppd/pdpm/chap_pdf/chapt29.pdf (698 KB PDF).