英格丽德·范豪滕-赫鲁内费尔德1086/111002. Zappala, V.; van Houten-Groeneveld, I. Pole coordinates of the asteroids 9 Metis, 22 Kalliope, and 44 NYSA (PDF). Icarus. 1979, 40 (2):
直笛直笛按其形制及生產時期,可分為中世紀直笛(Medieval recorder),如Dordrecht,Tartu及Nysa;文藝復興式直笛(Renaissance recorder),如Virdung,Gohin及Kynseker;前巴洛克直笛(early baroque