upward

V-group elements

J Wang, H Mizuseki, Y Kawazoe, T Hashizume, M Naitoh, D Wang, E Wang, Stability of Sb line structures on Si(001), PRB 67, 193307 (2003)

J H Owen, K Miki, H Koh, H W Yeom, D R Bowler, Stress relief as the driving force for self-assembled Bi nanolines, PRL 88, 226104 (2002)