https://research.ibm.com/publications/sub-angstrom-probe-size-in-hadf-stem-at-120kv
Sub-angstrom probe size in HADF-STEM at 120KV for Microscopy and Microanalysis - IBM Research
Sub-angstrom probe size in HADF-STEM at 120KV for Microscopy and Microanalysis by Philip Batson et al.