New type of near-infrared to visible photon upconversion in Tm2+-doped CsCaI3
Journal of the American Chemical Society (2006) - Comment
pubmed: 16522068  doi: 10.1021/ja0567790  issn: 0002-7863  issn: 1520-5126 

Eva Beurer, Judith Grimm, Pascal Gerner, Hans U. Güdel