Projective classification of jets of surfaces in $\mathbb{P}^4$
  We are interested in the local extrinsic geometry of smooth surfaces in 4-space, and classify jets of Monge forms by projective transformations according to $\mathcal{A}^3$-types of their central projections. 
Jorge Luiz Deolindo Silva and Yutaro Kabata
math.DG math.GT