Stroboscopy: Rigid: Female Vocal cords at high and low pitch - YouTube
Laryngeal Physiology. - ppt download
How Are Different Pitches Produced? – Voice Manual
How to Stay on Pitch (and Stop Singing Sharp or Flat!) - Blog - Worship Vocalist
About Your Voice - Successful Singing Backing Tracks
Why can I not make a high pitched 'whoo!' sound? All that comes out is a croaky/airy embarrassing squeak, as with most high pitched sounds I attempt. - Quora
Pitch and Frequency - Science News
Normal Voice Function | Sydney Voice & Swallowing
Anatomy Of How To Sing High Notes Without Strain - Throga - The Vocal Gym