Cullum, R. The watchers of the plains: A love story of the bad lands. Hodder & Stoughton.
Chicago-viite (17. p.)Cullum, Ridgwell. The Watchers of the Plains: A Love Story of the Bad Lands. London: Hodder & Stoughton.
MLA-viite (8. p.)Cullum, Ridgwell. The Watchers of the Plains: A Love Story of the Bad Lands. Hodder & Stoughton.
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