Vrijens, G. (1978). Visions for four Double Basses: Guibert Vrijens (Partitur + Stimmen.). Molenaar's Muziekcentrale.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रVrijens, Guibert. Visions for Four Double Basses: Guibert Vrijens. Partitur + Stimmen. Wormerveer/Holland: Molenaar's Muziekcentrale, 1978.
एमएलए (8वां संस्करण) प्रशस्ति पत्रVrijens, Guibert. Visions for Four Double Basses: Guibert Vrijens. Partitur + Stimmen. Molenaar's Muziekcentrale, 1978.
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