graph{
  start=42

  // Entities
  node [
    shape=box
    style=filled
    penwidth=1.5
    fillcolor="#FFFFFF"
  ]

  // Associative entities
  1 [label="CLIENT",shape=Mdiamond]

  // Normal entity attributes
  node [
    shape=oval
    penwidth=1.5
    fillcolor="#FFFFFF"
  ]

  // Weak and strong entity attributes
  2 [label=<<u>Réf.<br/>client</u>>]

  // Edges between entities and attributes
  edge [
    penwidth=1.5
  ]
  1 -- 2
}