Стиль цитування APA (7-ме видання)

Warren Penn, R. Foreword to Brother to Dragons: A Play in Two Acts / Robert Warren Penn. Robert Penn Warren's "Brother to Dragons" : a discussion.(1983).

Чикаго стиль цитування (17-те видання)

Warren Penn, Robert. "Foreword to Brother to Dragons: A Play in Two Acts / Robert Warren Penn." Robert Penn Warren's "Brother to Dragons" : A Discussion.(1983) .

Стиль цитування MLA (8-ме видання)

Warren Penn, Robert. "Foreword to Brother to Dragons: A Play in Two Acts / Robert Warren Penn." Robert Penn Warren's "Brother to Dragons" : A Discussion.(1983), .