1. Council Directive 1999/74/EC of 19 July 1999 laying down minimum standards for the protection of laying hens;Off J Eur Commun,1999
2. Council Regulation (EC) No. 1804/1999 of 19 July 1999 supplementing Regulation (EEC) No. 2092/91 on organic production of agricultural products and indications referring thereto on agricultural products and foodstuffs to include livestock production;Off J Eur Commun,1999
3. Commission Regulation (EC) No. 2295/2003 of 23 December 2003 introducing detailed rules for implementing Council Regulation (EEC) No. 1907/90 on certain marketing standards for eggs;Off J Eur Commun,2003
4. Shell strength of eggs from medium-bodied hybrid hens housed in cages or in range in outside pens;Hughes;Br Poultry Sci,1985
5. Egg quality as influenced by production systems;Belyavin;World Poultry Sci J,1988