Heisenberg

Substantivo propio

  had

Auxiliar

  been

Auxiliar

  studying

Verbo

  the

Determinador

  papers

Substantivo

  of

Adposición

  Paul

Substantivo propio

  Dirac

Substantivo propio

  and

Conxunción coordinadora

  Pascual

Substantivo propio

  Jordan

Substantivo propio

.

Heisenberg had been studying the papers of Paul Dirac and Pascual Jordan.

Heisenberg had been studying the papers of Paul Dirac and Pascual Jordan.