9Kundson R J, Clark D F, Kennedy T C, et al. Effect of aging alone on mechanical properties of the normal adult human lung [ J]. J Appl Physiol, 1977, 43: 1054.
10Knudson R J, Lebowitz M D, Holberg C J, et al. Changes in the normal maximal expiratory flow-volume curve with growth and aging [J]. Am Rev Respir Dis, 1983, 127: 725.