FAA AC (Advisory Circular) 120-87B, 14 pages long, detailing use of child restraint systems on aircraft. This information gets pretty technical as the intended audience is air carrier personnel and crew members who are familiar with the acronyms and the FAA's way of wording things, but could be useful in some cases for parents with questions regarding CRS use while flying:
http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgAdvisoryCircular.nsf/0/52b83b02fcc01375862577a60070fb65/$FILE/AC%20120-87B.pdf
http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgAdvisoryCircular.nsf/0/52b83b02fcc01375862577a60070fb65/$FILE/AC%20120-87B.pdf