分类： 若有所思

      前几天遇到一本英文计算机书，不知该如何入类。翻来翻去，发现版权页上印有ACM Computing Classification System分类号。手头没有这个分类法，就上网去找，很容易就找到了最新的1998版，除提供浏览外，还可以将网页保存下来脱机使用。根据书上给出的类，很快就确定了《中图法》类号。
      联想到在一些西文的数学书上，有时会有Mathematics Subject Classification号码。象上面的计算机图书一样，如果正好是数学小分支学科的书，这个分类法的号码很有参考价值。手头有本1980版Mathematics Subject Classification，破旧不堪，于是想到网上去看看有没有电子版的。一样很方便就找到了2000年版，除提供浏览、检索外，还可以下载PDF格式的完整版。

链接：
ACM Computing Classification System (1998 Version, valid in 2004)
美国计算机协会Association of Computing Machinery编制的计算机分类法。
2000 Mathematics Subject Classification （MSC 2000）
美国《数学评论》Mathematical Reviews和德国《数学文摘》Zentralblatt MATH所用分类法。

附二种分类一级类表：

 

ACM Computing Classification System一级类：
A. General Literature
B. Hardware
C. Computer Systems Organization
D. Software
E. Data
F. Theory of Computation
G. Mathematics of Computing
H. Information Systems
I. Computing Methodologies
J. Computer Applications
K. Computing Milieux

Mathematics Subject Classification一级类：
00-xx General
01-xx History and biography
03-xx Mathematical logic and foundations
04-xx This section has been deleted
05-xx Combinatorics
06-xx Order, lattices, ordered algebraic structures
08-xx General algebraic systems
11-xx Number theory
12-xx Field theory and polynomials
13-xx Commutative rings and algebras
14-xx Algebraic geometry
15-xx Linear and multilinear algebra; matrix theory
16-xx Associative rings and algebras
17-xx Nonassociative rings and algebras
18-xx Category theory; homological algebra
19-xx $K$-theory
20-xx Group theory and generalizations
22-xx Topological groups, Lie groups 
26-xx Real functions
28-xx Measure and integration
30-xx Functions of a complex variable
31-xx Potential theory
32-xx Several complex variables and analytic spaces
33-xx Special functions
34-xx Ordinary differential equations
35-xx Partial differential equations
37-xx Dynamical systems and ergodic theory
39-xx Difference and functional equations
40-xx Sequences, series, summability
41-xx Approximations and expansions
42-xx Fourier analysis
43-xx Abstract harmonic analysis
44-xx Integral transforms, operational calculus
45-xx Integral equations     
46-xx Functional analysis
47-xx Operator theory
49-xx Calculus of variations and optimal control; optimization
51-xx Geometry
52-xx Convex and discrete geometry
53-xx Differential geometry
54-xx General topology
55-xx Algebraic topology
57-xx Manifolds and cell complexes
58-xx Global analysis, analysis on manifolds 
60-xx Probability theory and stochastic processes
62-xx Statistics
65-xx Numerical analysis
68-xx Computer science
70-xx Mechanics of particles and systems
73-xx This section has been deleted
74-xx Mechanics of deformable solids
76-xx Fluid mechanics
78-xx Optics, electromagnetic theory
80-xx Classical thermodynamics, heat transfer
81-xx Quantum theory
82-xx Statistical mechanics, structure of matter
83-xx Relativity and gravitational theory
85-xx Astronomy and astrophysics
86-xx Geophysics
90-xx Operations research, mathematical programming
91-xx Game theory, economics, social and behavioral sciences
92-xx Biology and other natural sciences
93-xx Systems theory; control 
94-xx Information and communication, circuits
97-xx Mathematics education

 

    外文图书分类除了参考主题外，总要参考杜威十进分类法号DDC和国会图书馆分类法号LCC。想在我的链接”编目标准网站”中增加杜威十进分类法DDC，却发现挂在网上的多为旧版，而偏偏DDC最近两版在千分表（三位简表）上就有不少差异。现在链接的是DDC官方网站以PDF方式提供的22版千分表下载网址。

    其实对于编目来说，旧版分类法也很有用。毕竟国情所限，做旧书的时候也不少，套录记录时也常常见到20版、21版甚至更早版本的DDC号。现推荐DDC旧版：
√21版千分表：哈尔滨工业大学（威海分校）图书馆提供
√20版千分表：一位非专业人员在其个人网站提供
√13简版：加拿大Near North District School Board图书馆提供
据OCLC News Releases 1997年7月号说明，13简版（1997年出版）与21版（1996年出版）兼容。但经对比，该13简版内容似乎与20版更相近。特别之处在于，此表提供多至4位的类号，在网上很少见，参考性更高些。）

    网上免费的大概只能详细到4位类号了。如果愿意花钱，DDC的东家OCLC可以提供完整的联机电子版，即WebDewey。