+@Article{foell77,
+ title = "The formation of swirl defects in silicon by
+ agglomeration of self-interstitials",
+ journal = "Journal of Crystal Growth",
+ volume = "40",
+ number = "1",
+ pages = "90--108",
+ year = "1977",
+ note = "",
+ ISSN = "0022-0248",
+ doi = "DOI: 10.1016/0022-0248(77)90034-3",
+ URL = "http://www.sciencedirect.com/science/article/B6TJ6-46BWB4Y-44/2/bddfd69e99369473feebcdc41692dddb",
+ author = "H. Föll and U. Gösele and B. O. Kolbesen",
+ notes = "b-swirl: si + c interstitial agglomerates, c-si
+ agglomerate",
+}
+
+@Article{foell81,
+ title = "Microdefects in silicon and their relation to point
+ defects",
+ journal = "Journal of Crystal Growth",
+ volume = "52",
+ number = "Part 2",
+ pages = "907--916",
+ year = "1981",
+ note = "",
+ ISSN = "0022-0248",
+ doi = "DOI: 10.1016/0022-0248(81)90397-3",
+ URL = "http://www.sciencedirect.com/science/article/B6TJ6-46MD42X-90/2/a482c31bf9e2faeed71b7109be601078",
+ author = "H. Föll and U. Gösele and B. O. Kolbesen",
+ notes = "swirl review",
+}
+