Simple English Proper (Lumen Christi Gradual and Modal Responsorial Psalms). The Roman Missal gives us these Bible verses to be sung per the examples recorded: the congregation joins the cantor for the antiphon (printed), then the cantor sing the Psalm alone, then the congregation and cantor repeat the antiphon.
Roman Gradual – Ordinary Form of the Roman Rite
Download pages of the Gregorian Missal: GM Assumption
Responsorial (see “simple proper” above), or Gradual (cantor or schola alone)
Download Communion verses:
Extraordinary Form of the Roman Rite
Download pages of Mass & Vespers 1957 for the Assumption of the BVM