1. Reliability of Allen’s test in selection of patients for radial artery harvest 
Martin A Jarvis, Claire L Jarvis, BSc, Peter R.M Jones, PhD, Tomasz J Spyt 
The Annals of Thoracic Surgery 
Volume 70, Issue 4, Pages (October 2000)
DOI: /S (00)

2. Fig 1
Doppler ultrasound waveform recordings from the princeps pollicis artery (A) before and (B) during radial artery compression demonstrating no change in the arterial pulse waveform in a patient with an adequate ulnar collateral blood supply.
The Annals of Thoracic Surgery  , DOI: ( /S (00) )

3. Fig 2
Doppler ultrasound waveform recordings from the princeps pollicis artery (A) before and (B) during radial artery compression demonstrating significant damping of the arterial pulse waveform a patient with an inadequate ulnar collateral blood supply.
The Annals of Thoracic Surgery  , DOI: ( /S (00) )