{"created": {"type": "/type/datetime", "value": "2009-12-10T04:51:39.265981"}, "subjects": ["Data processing", "Filters (Mathematics)", "Mathematics", "Signal processing", "System analysis", "Signal theory (telecommunication)", "Electric filters"], "latest_revision": 4, "key": "/works/OL3915868W", "title": "Signals and filters", "authors": [{"type": {"key": "/type/author_role"}, "author": {"key": "/authors/OL712948A"}}], "type": {"key": "/type/work"}, "last_modified": {"type": "/type/datetime", "value": "2020-07-31T12:08:30.054852"}, "covers": [1231032], "revision": 4}