U. S. government publications

Federal Register, Resource Conservation and Recovery Act (RCRA), 42 US Code s/s 6901 et seq. 1976, U.S. Government, Public Laws, available at www.access.gpo.gov/uscode/title42/chapter82. html, January 2004. 

Federal Register, Clean Water Act (CWA), 33 U.S. Code ss/1251 et seq. 1977, U.S. Government, Public Laws, 2009. Available at http //www.access.gpo.gov/uscode/title33/chapter26. html... 

Figure 7.14. Relationship between Fe oxidation rate (k) and pH (from U.S. Government Publication, 1969).

Generally, it is not necessary to seek anyone s permission to use public domain works. However, when using material that appeared in a U.S. government publication, check the caption or reference section to see if credit is given to a source for which permission is required. 

Reminder Even though material in a U.S. government publication generally does not require permission to reproduce it,sometimes government publications include material that is protected by copyright. Always check the caption or reference section to determine whether you need to obtain permission to reproduce it. 

---