@misc{indiciae29be64342583,
  title = {Space Mission Concept Development Using Concept Maturity Levels},
  author = {Wessen, Randii R. and Borden, Chester and Ziemer, John and Kwok, Johnny},
  year = {2013},
  url = {https://ntrs.nasa.gov/citations/20150007816},
  note = {Source identifier: 20150007816}
}