Zhao, Yan; Yu, Zicheng; Zhao, Cheng (23 April 2010). "Hemlock (Tsuga canadensis) declines at 9800 and 5300 cal. yr BP caused by Holocene climatic shifts in northeastern North America". The Holocene. 20 (6): 877–886. Bibcode:2010Holoc..20..877Z. doi:10.1177/0959683610365932. S2CID220988296.
Zhao, Yan; Yu, Zicheng; Zhao, Cheng (23 April 2010). "Hemlock (Tsuga canadensis) declines at 9800 and 5300 cal. yr BP caused by Holocene climatic shifts in northeastern North America". The Holocene. 20 (6): 877–886. Bibcode:2010Holoc..20..877Z. doi:10.1177/0959683610365932. S2CID220988296.
Zhao, Yan; Yu, Zicheng; Zhao, Cheng (23 April 2010). "Hemlock (Tsuga canadensis) declines at 9800 and 5300 cal. yr BP caused by Holocene climatic shifts in northeastern North America". The Holocene. 20 (6): 877–886. Bibcode:2010Holoc..20..877Z. doi:10.1177/0959683610365932. S2CID220988296.