On the relations of isotonian algebras
  It is shown that for large classes of posets $P$ and $Q$, the defining ideal $J_{P,Q}$ of an isotonian algebras is generated by squarefree binomials. Within these classes, those posets are classified for which $J_{P,Q}$ is quadratically generated. 
J\"urgen Herzog, Ayesha Asloob Qureshi, Akihiro Shikama
math.AC