digraph "api-data-model" {
  node [shape=ellipse];

  person;
  org;
  contract;
  project;
  card;
  report;
  competence;

  contract -> person;
  contract -> org;
  contract -> project;

  card -> org;
  card -> person;

  report -> org;
  report -> contract;
  report -> project;

  competence -> person;
  competence -> org;
}