At the time of the Serbian retreat he had been working on an epic poem, Cain, in which he compared Bulgaria's attack on Serbia (that precipitated the retreat) to the biblical story of Cain and Abel.
La momentul retragerii sârbe a lucrat la un poem epic, Cain, în care a comparat atacul Bulgariei asupra Serbiei (care a precipitat retragerea) cu povestea biblică a lui Cain și Abel.