Here is the poem at page 259 of Oerberg's Lingua Latina Per Se Illustrata - Familia Romana;
Quisquis amat valeat, pereat qui nescit amare
Bis tanto pereat quisquis amare vetat.
which was as the marginal note points out inventa est Pompeiis in oppido Campaniae
Quisquis Amat
As a fuller example, here is a pdf of a familiar poem -
Catullus 13