“…Moreover a whole subject has developed concerning noncommutative manifolds and for lack of space we shall not cover it here but refer to the papers [69-72, 99, 111, 112, 189]. We apologise for the brevity of our account of the topics covered in the present survey and the reader will find a more complete treatment and bibliography in the collection of surveys [35,90,104,114,117,124,134,195,199,272,276,281] to be published by Springer.…”