SOMERVILL, B. A. (2006). WILLIAM PENN FOUNDER OF PENNSYLVANIA. COMPASS POINT BOOKS.
Chicago-čujuhus (17. p.)SOMERVILL, BARBARA. A. WILLIAM PENN FOUNDER OF PENNSYLVANIA. MINNEAPOLIS: COMPASS POINT BOOKS, 2006.
MLA-čujuhus (9. p.)SOMERVILL, BARBARA. A. WILLIAM PENN FOUNDER OF PENNSYLVANIA. COMPASS POINT BOOKS, 2006.
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