Evidence of phase transitions in heart period dynamics. - Henrik Bettermann; Peter Van Leeuwen (Biol. Cybern., 1998)

Detecting cardiorespiratory Coordination by Respiratory Pattern Analysis of Heart Period Dynamics - the Musical rhythm Approach. - Henrik Bettermann; Dirk Cysarz; Peter Van Leeuwen (Int. J. Bifurc. Chaos, 2000)