The Free On-line Dictionary of Computing (19 January 2023):

Bachman Diagram
Data Structure Diagram

    (Or "Data Structure Diagram") Charles Bachman's 1969
   proposal for a style of entity-relationship model which
   differs from that of Peter Chen.  Backman Diagrams show both
   entities and relations as boxes connected by "couplings".
   Couplings are named to show how that entity participates in
   that relation.  Each end of a coupling is marked to show the
   cardinality (one or many) of the entity in the relation.

   (https://cio-wiki.org/wiki/Bachman_Diagram).

   [Charles W. Bachman. "Data structure diagrams". Data Base,
   1969, 1(2):4–10].

   (1995-02-08)