1.

M. A. Arbib and E. G. Manes,*Arrows, Structures, and Functors*, Academic Press, New York, 1975.

2.

G. Berry and J.-J. Levy, Minimal and optimal computations of recursive programs,*J. ACM* 26 (1979), 148–175.

3.

G. Birkhoff and J. D. Lipson, Heterogeneous algebras,*J. Combinatorial Theory*, 8 (1970), pp. 115–133.

4.

V. Claus, H. Ehrig, and G. Rozenberg (Editors),*Graph Grammars and their Application to Computer Science and Biology*, Lecture Notes in Computer Sci., 73 (1979).

5.

E. F. Codd,*A relational model of data for large shared data banks*, Comm. ACM, 13 (1970), pp. 377–387.

6.

J. A. Darringer and W. H. Joyner,*A new look at logic synthesis*, IBM Research Report RC 8268, Yorktown Heights NY, May 1980.

7.

H. Ehrig and H.-J. Kreowski, Contributions to the algebraic theory of graph grammars,*Math. Nachr.*, to appear.

8.

H. Ehrig and H.-J. Kreowski, Applications of graph grammar theory to consistency, synchronization, and scheduling in data base systems,*Information Sciences*, to appear.

9.

H. Ehrig, H.-J. Kreowski, A. Maggiolo-Schettini, B. K. Rosen, and J. Winkowski, Deriving structures from structures,*Lecture Notes in Computer Science*, 64 (1978), pp. 177–190.

10.

H. Ehrig, M. Pfender, and H. J. Schneider, Graph grammars: an algebraic approach,*Proc. 14th Ann. IEEE Symp. on Switching and Automata Theory*, Iowa City, October 1973, pp. 167–180.

11.

H. Ehrig and B. K. Rosen,*Commutativity of independent transformations on complex objects*, IBM Research Report RC 6251, Yorktown Heights NY, October 1976.

12.

H. Ehrig and B. K. Rosen, The mathematics of record handling,*SIAM J. Computing*, 9 (1980), 441–469.

13.

H. Ehrig and B. K. Rosen,*Commutativity, parallelism, and concurrency for transformations of structures*, Bericht 79–21, Fachbereich Informatik, Tech. U. Berlin, October 1979.

14.

H. Ehrig and K. W. Tischer, Graph grammars and applications to specialization and evolution in biology,*J. Computer and System Sci.*, 11 (1975), pp. 212–236.

15.

S. Eilenberg and J. Wright, Automata in general algebras,*Information and Control*, 11 (1967), 452–470.

16.

R. Farrow, K. Kennedy, and L. Zucconi, Graph grammars and global program data flow analysis,*Proc. 17th Ann. IEEE Symp. on Foundations of Computer Sci.*, Houston, October 1976, pp. 42–56.

17.

H. Herrlich and G. Strecker,*Category Theory*, Allyn and Bacon, Rockleigh, New Jersey, 1973.

18.

H.-J. Kreowski,*Ein Pumpinglemma für Kanten-Kontextfreie Graph-Sprachen*, Bericht 77–15, Fachbereich Informatik, Tech. U. Berlin, September 1977. (See also [4].)

19.

M. J. O'Donnell, Computing in systems described by equations,*Lecture Notes in Computer Science*, 58 (1977).

20.

G. Pacini, C. Montangero, and F. Turini, Graph representation and computation rule for typeless recursive languages,*Lecture Notes in Computer Science*, 14 (1974), pp. 157–169.

21.

Padawitz, P.,*Graph grammars and operational semantics*, Bericht 78–33, Fachbereich Informatik, Tech. U. Berlin, October 1978. (See also [4].)

22.

V. Rajlich, Dynamics of discrete systems ⋯,*J. Computer and System Sci.*, 11 (1975), pp. 186–202.

23.

B. K. Rosen, Deriving graphs from graphs by applying a production,*Acta Informatica*, 4 (1975), pp. 337–357.

24.

H. J. Schneider and H. Ehrig, Grammars on partial graphs,*Acta Informatica*, 6 (1976), pp. 297–316.

25.

J. Staples, A class of replacement systems with simple optimality theory,*Bull. Austral. Math. Soc.*, 17 (1977), p. 335–350.

26.

J. Staples, Computation on graph-like expressions,*Theoretical Computer Sci.*, 10 (1980), 171–185.

27.

J. Staples, Optimal evaluations of graph-like expressions,*Theoretical Computer Sci.*, 10 (1980), 297–316.

28.

J. Staples, Speeding up subtree replacement systems,*Theoretical Computer Sci.*, 11 (1980), 39–47.

29.

S. A. Vere, Relational production systems,*Artificial Intelligence*, 8 (1977), pp. 47–68.

30.

J. Vuillemin, Correct and optimal implementations of recursion in a simple programming language,*J. Computer and System Sci.*, 9 (1974), pp. 332–354.