<Li> Jump up ^ Sr (I) has been observed in strontium monofluoride (SrF); see P. Colarusso; Guo, B.; Zhang, K. - Q.; Bernath, P.F.; et al. (1996). "High - Resolution Infrared Emission Spectrum of Strontium Monofluoride" (PDF). J. Molecular Spectroscopy. 175: 158--171 . Bibcode: 1996JMoSp. 175...158C . doi: 10.1006 / jmsp. 1996.0019 . Archived from the original (PDF) on 2012 - 03 - 08 . </Li> <Li> Jump up ^ Y (I) has been observed in yttrium (I) bromide (YBr); see "Yttrium: yttrium (I) bromide compound data". OpenMOPAC.net . Archived from the original on 2011 - 07 - 23 . Retrieved 2007 - 12 - 10 . </Li> <Li> Jump up ^ Y (II) has been observed in ((18 - crown - 6) K) ((C H SiMe) Y); see MacDonald, M.R.; Ziller, J.W.; Evans, W.J. (2011). "Synthesis of a Crystalline Molecular Complex of Y, ((18 - crown - 6) K) ((C H SiMe) Y)". J. Am. Chem. Soc. 133 (40): 15914--17 . doi: 10.1021 / ja207151y . </Li> <Li> Jump up ^ Zr (− 1) has been reported in (Zr (bipy)) (see Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed .). Butterworth - Heinemann . p. 960 . ISBN 0 - 08 - 037941 - 9 . and Holleman, Arnold F.; Wiberg, Egon; Wiberg, Nils (1995). "Zirconium". Lehrbuch der Anorganischen Chemie (in German) (101 ed .). Walter de Gruyter . p. 1413 . ISBN 3 - 11 - 012641 - 9 .), but was later shown to be Zr (+ 4); see Bowman, A.C.; England, J.; Sprouls, S.; Weihemüller, T.; Wieghardt, K. (2013). "Electronic structures of homoleptic (tris (2, 2' - bipyridine) M) n complexes of the early transition metals (M = Sc, Y, Ti, Zr, Hf, V, Nb, Ta; n = 1 +, 0, 1 -, 2 -, 3 -): an experimental and density functional theoretical study". Inorganic Chemistry . 52 (4): 2242--56 . doi: 10.1021 / ic302799s . PMID 23387926 . </Li>

What is the oxidation number of bismuth in bi(oh)3