Philadelphia Museum of Art, Shoemaker, I. H., Helfand, W. H., & Ittmann, J. W. (2011). Health for sale: Posters from the William H. Helfand collection : interview with William H. Helfand. Philadelphia Museum of Art.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रPhiladelphia Museum of Art, Innis H. Shoemaker, William H. Helfand, और John W. Ittmann. Health for Sale: Posters from the William H. Helfand Collection : Interview with William H. Helfand. Philadelphia, PA: Philadelphia Museum of Art, 2011.
एमएलए (8वां संस्करण) प्रशस्ति पत्रPhiladelphia Museum of Art, et al. Health for Sale: Posters from the William H. Helfand Collection : Interview with William H. Helfand. Philadelphia Museum of Art, 2011.
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