"Openwork." Grove Art Online, Oxford Art Online. Oxford University Press, accessed May 26, 2015, subscription required. Their article reads, in full: "Any form of decoration that is perforated". OED "Openwork", 1, where all examples cited from earlier than 1894 are hyphenated, though this is now less common than the single word.
Diane Favro, et al. "Rome, ancient, s 5, ii." Grove Art Online. Oxford Art Online. Oxford University Press, accessed May 27, 2015, subscription required
Timothy Taylor. "Scythian and Sarmatian art." Grove Art Online, Oxford Art Online. Oxford University Press, accessed May 27, 2015, subscription required
