R.K.S. Yadav, Brijesh Kumar, A. Subramaniam, Ram Sagar et Blesson Mathew, « Optical and near-IR photometric study of the open cluster NGC 637 and NGC 957 », MONTHLY NOTICES of the Royal Astronomical Society, vol. 390-3, , p. 985-986 (DOI10.1111/j.1365-2966.2008.13740.x, lire en ligne)
R.K.S. Yadav, Brijesh Kumar, A. Subramaniam, Ram Sagar et Blesson Mathew, « Optical and near-IR photometric study of the open cluster NGC 637 and NGC 957 », MONTHLY NOTICES of the Royal Astronomical Society, vol. 390-3, , p. 985-986 (DOI10.1111/j.1365-2966.2008.13740.x, lire en ligne)