by Fuchikami, Manabu, Morinobu, Shigeru, Segawa, Masahiro, Okamoto, Yasumasa, Yamawaki, Shigeto, Ozaki, Norio, Inoue, Takeshi, Kusumi, Ichiro, Koyama, Tsukasa, Tsuchiyama, Kounosuke, Terao, Takeshi
Published in PloS one (30.08.2011)

by Keidar, Anat, Hurtig, Richard R., Titze, Ingo R.
Published in Journal of voice (1987)

by Ludlow, L H, Levy, S
Published in Journal of pediatric psychology (01.09.1984)