Your pictures do not appear to be working, however--as long as the BCD (which you should measure to be sure) and number of chainring bolts match, you can use pretty much anything. Try to match the rings with the appropriate number of speeds (probably 7/8, given the product name you posted), but you aren't limited to Shimano. You may be able to find whole chainring sets from Vuelta, Sugino, Raceface, among others.