@online{huangndsobolev,
  author       = {Huang, Xuanqiang Angelo},
  title        = {Sobolev Spaces},
  organization = {Xuanqiang Angelo Huang's Blog},
  url          = {https://flecart.github.io/notes/sobolev-spaces/},
  langid       = {english},
  abstract     = {Sobolev Spaces \# Motivation \&\#x26; Setup \# PDE theory and the calculus of variations require function spaces in which (i) differentiation makes sense for non-smooth functions, (ii) the space is complete under an L p -flavored norm, and (iii) one can embed into L q or Hölder space}
}