Song, S.-M., Lee, J.-K., & Waldron, K. (1987). Motion Study of Two- and Three-Dimensional Pantograph Mechanisms. Mechanism and Machine Theory. https://doi.org/10.1016/0094-114X(87)90021-8
Song, Shin-Min, Jong-Kil Lee, and Kenneth Waldron. 1987. “Motion Study of Two- and Three-Dimensional Pantograph Mechanisms”. Mechanism and Machine Theory. https://doi.org/10.1016/0094-114X(87)90021-8.
Song, S.-M., J.-K. Lee, and K. Waldron. Motion Study of Two- and Three-Dimensional Pantograph Mechanisms. Mechanism and Machine Theory, 1 Jan. 1987, doi:10.1016/0094-114X(87)90021-8.