Hung, Do Trong, Nguyen Van Khang, Do Sanh, Banh Xuan Tho, and Ho Dac Tho. 1982. “Some Dynamical Calculations of a Transducer of Two Constact Points Type With Two Degrees of Freedom”. Vietnam Journal of Mechanics 4 (4). Hanoi, Vietnam:19-26. https://doi.org/10.15625/0866-7136/10471.