https://www.cosmos.esa.int/web/herschel/ao2-how-to-step-by-step-guide
COSMOS Announcement of Opportunity (AO-2) - 'how-to' step-by-step guide - Herschel - Cosmos
announcement of opportunity
https://www.stsci.edu/stsci-research/fellowships/nasa-hubble-fellowship-program/announcement-of-opportunity
Announcement of Opportunity | STScI
Find in-depth information about the NASA Hubble Fellowship Program (NHFP) and its requirements.
announcement of opportunity