Although the copyright page is dated 1968 with no later impressions or editions, as the dustwrapper flap is priced at £1.25, it would have been published in or after February 1971 when the UK decimalised its currency. In addition, the Collins' address on the title page ends in SW1 so the book would have been published before the SW1A postcodes were introduced in this area of London - the whole country was completed by 1974. The book also has a 10 digit ISBN number, these were introduced in 1970. Our conclusion is that the book is probably the first post-decimalisation and hence second impression published in early 1971.