Tham khảo Biến thiên thế tục

  1. ↑ Edwards, R.; McGee, J.; Bessetti, W. H. C. (2007). Technical Analysis of Stock Trends. CRC Press. tr. 17. ISBN 978-0-8493-3772-7. 
  2. ↑ Bretagnon, P. (1982). “Théorie du mouvement de l'ensemble des planètes. Solution VSOP82”. Astronomy & Astrophysics 114. tr. 278–288. Bibcode:1982A&A...114..278B.  |url= trống hay bị thiếu (trợ giúp)
  3. ↑ Merrill, Ronald T.; McElhinny, Michael W.; McFadden, Phillip L. (1996). The Magnetic Field of the Earth: Paleomagnetism, the Core, and the Deep Mantle. International Geophysics Series 63. Academic Press. ISBN 978-0124912465. 
  4. ↑ Okasha, M; McCarron, P; McEwen, J; Smith, GD (2001). “Age at menarche: secular trends and association with adult anthropometric measures”. Annals of Human Biology 28 (1): 68–78. PMID 11201332. doi:10.1080/03014460150201896. 
  5. ↑ Wattigney, WA; Srinivasan, SR; Chen, W; Greenlund, KJ; Berenson, GS (1999). “Secular trend of earlier onset of menarche with increasing obesity in black and white girls: the Bogalusa Heart Study”. Ethnicity & Disease 9 (2): 181–189. PMID 10421080. 
  6. ↑ Prentice, S; Fulford, AJ; Jarjou, LM; Goldberg, GR; Prentice, A (2010). “Evidence for a downward secular trend in age of menarche in a rural Gambian population”. Annals of Human Biology 37 (5): 717–721. PMC 3575631. PMID 20465526. doi:10.3109/03014461003727606. 
  7. ↑ Rokade, Shrikant; Mane, Arati (2008), “A Study Of Age At Menarche, The Secular Trend And Factors Associated With It”, The Internet Journal of Biological Anthropology 3 (2), doi:10.5580/115b 
  8. ↑ Biro, Frank; Galvez, MP; Greenspan, LC; Succop, PA; Vangeepuram, N (tháng 9 năm 2010), “Pubertal assessment method and baseline characteristics in a mixed longitudinal study of girls”, Pediatrics 126 (3): e583–90, PMC 4460992, PMID 20696727, doi:10.1542/peds.2009-3079 
  9. ↑ Euling, Susan; Herman-Giddens, Marcia; Lee, Peter; Selevan, Sherry (tháng 2 năm 2008). “Examination of US Puberty-Timing Data from 1940 to 1994 for Secular Trends: Panel Findings”. Pediatrics 121 (3).