When I try and use NetblockTool to search for Amazon Technologies Inc. (AT-88-Z) with or without the Inc I cannot produce any netblocks though they have dozens of /16 and even several /9 netblocks.
When I search Amazon and include subsidiaries I do not find those netblocks output by the tool. It is a non-trivial portion of the IPV4 space apparently missed. I'll try and dig into it why they're missed but I thought I should bring it to your attention.