数学策略和物理策略之间的相互交融已在导论中详细描述;也可参见Michel Janssen and Jurgen Renn,"Untying the Knot:How Einstein Found His Way Back to Field Equations Discarded in the Zurich Notebook",in The Genesis of General Relativity,vol.2,839 - 925.
p.15参见Karin Reich,Die Entwicklung des Tensorkalkuls:vom absoluten Differentialkalkul zur Relativ