C. M. Tan and S. Zukotynski. “Single Wafer Miniature Hall-Effect Keyboard,” IEEE Transactions on Industrial Electronics, vol. 36, no. 3, pp. 446-450, 1989.
https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=31509
C. M. Tan and S. Zukotynski. “Single Wafer Miniature Hall-Effect Keyboard,” IEEE Transactions on Industrial Electronics, vol. 36, no. 3, pp. 446-450, 1989.
https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=31509