This is the third version of a book on differential manifolds. The first version appeared in 1962, and was written at the very beginning of a period of great expansion of the subject. At the time, I found no satisfactory book for the foundations of the subject, for multiple reasons. I expanded the book in 1971, and I expand it still further today. Specifically, I have added three chapters on Riemannian and pseudo Riemannian geometry, that is, covariant derivatives, curvature, and some applications up to the Hopf-Rinow and Hadamard-Cartan theorems, as well as some calculus of variations and applications to volume forms. I have rewritten the sections on sprays, and I have given more examples of the use of Stokes' theorem. I have also given many more references to the literature, all of this to broaden the perspective of the book, which I hope can be used among things for a general course leading into many directions. The present book still meets the old needs, but fulfills new ones.

本书是有限元方面的经典教材。作者荟萃了近十几年来有限元领域研究的成果，对1989年的第3版重新组织并作了全面修订。新版共有18章，分为部分：1～6章讲述了有限元的概念和基本理论；7～10章侧重介绍有限元通用的分析方法和应用技能，其中有专门章节论述了误差估计和收敛问题；11～18章详述了有限元在结构动力学、热传导和流体、回转体、非线性、板和壳等方面的工程应用。全书既注重从物理概念上阐述有限元的基本理论，又强调提高应用能力，含有许多应用实例。 本书适合机械、力学、土木、动力、材料、水利和航空航天等专业高年级本科生和研究生作为有限元课程的教材及教学参考书，对相关专业的工程技术人员和科研工作者也有很好的参考价值。

《射影几何趣谈》(作者冯克勤)深入地探讨和介绍了射影几何这一几何分支的基本内容，并讲述了平面射影几何当中一些有趣的定理和概念。同时通过大量的例子来说明，如何利用射影几何的知识和方法解决平面几何学中的问题。《射影几何趣谈》适合初、高中师生，以及高等师范类院校数学教育专业的大学生和数学爱好者参考阅读。