Respond to these showcases www. ajplus. co. uk/ajdirect Readers may obtain information about these products by filling in the enquiry numbers on an AJ enquiry card. Advertisers wishing to promote their products on these pages should The latest edition of the British White Book is now online at www.british-gypsum. com/whitebook.Following research with users, design guidance has been expanded while system information is more compact, focusing on performance data.