1. AAFC 1993. Recommended code of practice for the care and handling of farm animals: Pigs. Agriculture and Agri-Feed Canada Publication 1898/E, Ottawa, Canada. p. 55.
2. Measurement in medicine: the analysis of method comparison studies;Altman;The Statistician,1983
3. Effect of stocking arrangement on pig performance;Chapple,1993
4. Experimental Design 2nd edition;Cochran,1957
5. European Community 2001. European Council Directive 2001/88/EC of 23rd October 2001 amending directive 91/630/EEC laying down minimum standards for the protection of pigs. Official Journal L316.