Geary, R. (1964). Correcting for Seasonality: 2. Correction of Moving Averages for Trend, especially at High or Low Turning Points, Memorandum Series 17, Dublin: ESRI, https://www.esri.ie/publications/correcting-for-seasonality-2-correction-of-moving-averages-for-trend-especially-at-high-or-low-turning-points