Well, they are in the Liber Usualis at the appropriate Sunday, common, or feast day for the older Roman office. The Liber Antiphonarius also has the weekdays with the parts needed to sing the full ferial office. Same for the Antiphonale Monasticum 1934.

For the Liturgia Horarum, the modern Antiphonale Romanum, v. 1, has the Solesmes assignments. The Vatican’s official list is slightly different. Anyway, the book will always have at least the first half of the Magnificat printed with the chant (including the solemn tone of feasts) that corresponds to the antiphon (which of course tells you which tone to use) and the Liber prints it with the psalm ending, the antiphonal (all versions) prints just the first half and expects you to memorize the rest, since it’s the same ending as the ordinary psalm endings. There is also a modern Antiphonale Monasticum. Same story.