那挺酷的——你可能会喜欢 Underwood Dudley 写的关于初等数论（Elementary Number Theory）的那本书。它涵盖的主题差不多，而且我觉得它的习题更多，还带了一部分答案。另外价格也不贵！
That's cool -- you might like Underwood Dudley's book on Elementary Number Theory. It has a similar set of topics, and I think it has more exercises and contains some solutions. And it's inexpensive!
…on any topic which interests you, read through it, and do a significant number of the exercises. You might try Epp's Discrete Mathematics, Hefferon's Linear Algebra, Colley's Vector Calculus, Dudley's Elementary Number Theory, Spivak or Apostol's Calculus (these go far beyond ordinary freshman calculus), Pinter's A Book of Abstract Algebra, among many others. Some of these books are expensive to buy new, but just buy older…
最近淘到的宝贝里：Underwood Dudley 的《Elementary Number Theory》（初等数论）很容易让人喜欢。你真能看出它是为了积极思考的读者而写的，里面配了一套很好且完全做得出来的正文习题、核心问题和补充题。内容……
Of recent gems: Elementary Number Theory by Underwood Dudley is easy to like. You can really see how it was written with an active reader in mind, with a good and doable set of inline excercises, key problems and additional problems. The material…
Underwood Dudley 写的《Elementary Number Theory》太棒了。另外，我也极力附和 tokenadult 对 Stillwell 所有书的推荐，那些书被顶到最高票完全是实至名归。
"Elementary Number Theory" by Underwood Dudley is great. Also, I enthusiastically second tokenadult's recommendations of all of Stillwell's books, which has quite rightly been voted to the top.
…personally like to get a book, see if I like the topic, and if I do then get another book so that I can compare them. You might try one of these elementary books on number theory: https://www.amazon.com/Elementary-Number-Theory-Second-Mathe... https://www.amazon.com/Introduction-Number-Theory-MIT-Press/... https://artofproblemsolving.com/store/book/intro-number-theo... Combinatorics and graph theory are reasonable too, but…
那挺酷的——你可能会喜欢 Underwood Dudley 写的关于初等数论（Elementary Number Theory）的那本书。它涵盖的主题差不多，而且我觉得它的习题更多，还带了一部分答案。另外价格也不贵！
That's cool -- you might like Underwood Dudley's book on Elementary Number Theory. It has a similar set of topics, and I think it has more exercises and contains some solutions. And it's inexpensive!
……挑任何你感兴趣的主题，通读一遍，然后做相当数量的习题。你可以试试 Epp 的《离散数学》、Hefferon 的《线性代数》、Colley 的《向量微积分》、Dudley 的《初等数论》、Spivak 或 Apostol 的《微积分》（这些可比大一普通的微积分深得多）、Pinter 的《抽象代数之书》等等。这些书里有些买新书很贵，但买旧书就行……
…on any topic which interests you, read through it, and do a significant number of the exercises. You might try Epp's Discrete Mathematics, Hefferon's Linear Algebra, Colley's Vector Calculus, Dudley's Elementary Number Theory, Spivak or Apostol's Calculus (these go far beyond ordinary freshman calculus), Pinter's A Book of Abstract Algebra, among many others. Some of these books are expensive to buy new, but just buy older…
最近淘到的宝贝里：Underwood Dudley 的《Elementary Number Theory》（初等数论）很容易让人喜欢。你真能看出它是为了积极思考的读者而写的，里面配了一套很好且完全做得出来的正文习题、核心问题和补充题。内容……
Of recent gems: Elementary Number Theory by Underwood Dudley is easy to like. You can really see how it was written with an active reader in mind, with a good and doable set of inline excercises, key problems and additional problems. The material…
Underwood Dudley 写的《Elementary Number Theory》太棒了。另外，我也极力附和 tokenadult 对 Stillwell 所有书的推荐，那些书被顶到最高票完全是实至名归。
"Elementary Number Theory" by Underwood Dudley is great. Also, I enthusiastically second tokenadult's recommendations of all of Stillwell's books, which has quite rightly been voted to the top.
答案永远是 David Burton 写的《Elementary Number Theory》。我从初一（7年级）就开始读这本书了。
The answer is always Elementary Number Theory by David Burton. I read this book since 7th grade.
……我个人喜欢买一本书，看看自己喜不喜欢这个主题，如果喜欢就再买一本拿来对照着看。你可以试试这几本数论的入门书：https://www.amazon.com/Elementary-Number-Theory-Second-Mathe... https://www.amazon.com/Introduction-Number-Theory-MIT-Press/... https://artofproblemsolving.com/store/book/intro-number-theo... 组合数学和图论也挺不错的，不过……
…personally like to get a book, see if I like the topic, and if I do then get another book so that I can compare them. You might try one of these elementary books on number theory: https://www.amazon.com/Elementary-Number-Theory-Second-Mathe... https://www.amazon.com/Introduction-Number-Theory-MIT-Press/... https://artofproblemsolving.com/store/book/intro-number-theo... Combinatorics and graph theory are reasonable too, but…