re: Sources
Charts from the world glacier monitoring service can be found here.
Heavy-duty documentation on the 2000/2001 report (BIG file) can be found here. Haven't read through it, but it's there if you want it. It may contain important information, such as why the 30 or so glaciers that have been monitored back to 1980 were selected for monitoring out of the 160,000 or so on Earth.
That the trend for the monitored glaciers--at least over the past 20 years--is downward, is not arguable. It's not clear what's causing the regular cycling, or why 2003 was so extreme.