To cite package ‘knfi’ in publications use:

  Park S (2022). _Development of an Algorithm for the Analysis of
  Korean National Forest Inventory Data : Focusing on Biodiversity and
  Biomass in Gangwon-do_. Master's thesis, Kookmin University, 77,
  Jeongneung-ro, Seongbuk-gu, Seoul, Republic of Korea.

A BibTeX entry for LaTeX users is

  @MastersThesis{,
    title = {Development of an Algorithm for the Analysis of Korean National Forest Inventory Data : Focusing on Biodiversity and Biomass in Gangwon-do},
    author = {Sinyoung Park},
    school = {Kookmin University},
    address = {77, Jeongneung-ro, Seongbuk-gu, Seoul, Republic of Korea},
    year = {2022},
  }