痕量同位素(原始内容 (PDF)存档于2011-07-22). Wilcken, K.~M.; Barrows, T. T.; Fifield, L. K.; Tims, S. G.; Steier, P. AMS of natural 236 U and 239Pu produced in uranium ores
霍桑大桥Park Service. November 23, 2012 [April 24, 2013]. (原始内容存档于2016-03-12). Tims, Dana. Four Multnomah County bridges listed on National Register of Historic