Optical data on cryogenic ices
N
2
Grundy, Schmitt, and Quirico 1993,
Icarus
105,
254-258.
H
2
O
Grundy and Schmitt 1998,
J. Geophys. Res.
103,
25,809-25,822.
CH
4
Grundy, Schmitt, and Quirico 2002,
Icarus
155,
486-496.
CH
3
D
Grundy et al. 2011,
Icarus
212,
941-949.
Lots more are on the way...