Nachum, Iris; Schaefer, Sagi. The Semantics of Political Integration: Public Debates about the Term ‘Expellees’ in Post-War Western Germany. Cambridge University

Rokopellidae Starobogatov & Moskalev, 1987; = Micropilinidae Haszprunar & Schaefer, 1997) Tergomya - Fossiilid.info. [2023-05-05]. （原始内容存档于2023-05-05） （英语）

Exemptions and Sales Tax Regressivity （页面存档备份，存于互联网档案馆）, By Jeffrey M. Schaefer, The American Economic Review, Vol. 59, No. 4, Part 1 (Sep., 1969), pp

  Fink, Carole; Schaefer, Bernd (编). Ostpolitik, 1969–1974: European and Global Responses. 2009.  Fulbrook, Mary. History of Germany, 1918–2000: the divided

兩相交數也不大於相交數。然而，哈納尼-塔特定理（英语：Hanani–Tutte theorem）說明，若這三個數中有任何一個為零，則皆為零。 Schaefer （2014, 2018）綜述了許多變式。 http://terrytao.wordpress.com/2007/09/18/the-cros