1. Akiyama, K. et al. [Event Horizon Telescope Collaboration] (2019). First M87 event horizon telescope results. I. The shadow of the supermassive black hole. Astrophys. J. Lett., 875, L1.
2. Akiyama, K. et al. [Event Horizon Telescope Collaboration] (2019). First M87 event horizon telescope results. II. Array and instrumentation. Astrophys. J. Lett., 875, L2.
3. Akiyama, K. et al. [Event Horizon Telescope Collaboration] (2019). First M87 event horizon telescope results. III. Data processing and calibration. Astrophys. J. Lett., 875, L3.
4. Akiyama, K. et al. [Event Horizon Telescope Collaboration] (2019). First M87 event horizon telescope results. IV. Imaging the central supermassive black hole. Astrophys. J. Lett., 875, L4.
5. Akiyama, K. et al. [Event Horizon Telescope Collaboration] (2019). First M87 event horizon telescope results. V. Physical origin of the asymmetric ring. Astrophys. J. Lett., 875, L5.