References ^ Cohn, Jay N., M.D.; Francis, Gary S., M.D. (2014). Stage B, a Pre-Cursor of Heart Failure, Elsevier Science Health Science div. BiggerBooks. ISBN 9781455738724 (revised May 2022)^ (2013). Stage B, a Pre-Cursor of Heart Failure ECampus. ISBN 9781455738724 (revised Oct 2016)