Case, William. "Two ways of driving a child's swing". Archived from the original on 9 December 2011. Retrieved 27 November 2011. Note: In real-life playgrounds, swings are predominantly driven, not parametric, oscillators.
Case, William. "Two ways of driving a child's swing". Archived from the original on 9 December 2011. Retrieved 27 November 2011. Note: In real-life playgrounds, swings are predominantly driven, not parametric, oscillators.