Standard setting anchor statements: a double cross-over trial of two different methods oleh Steven Burr, Theresa Martin, James Edwards, Colin Ferguson, Kerry Gilbert, Christian Gray, Adele Hill, Joanne Hosking, Karen Johnstone, Jolanta Kisielewska, Chloe Milsom, Siobhan Moyes, Ann Rigby-Jones, Iain Robinson, Nick Toms, Helen Watson, Daniel Zahra