Walter Block  , 
    Homesteading, Ad Coelum, Owning Views and Forestalling,
    The Social Sciences,
    Volume 3,Issue 2,
    2008,
    Pages 96-103,
    ISSN 1818-5800,
    sscience.2008.96.103,
    (https://makhillpublications.co/view-article.php?doi=sscience.2008.96.103)
    Abstract: Homesteading, not the ad coelum doctrine, is compatible with libertarianism. In the former case, one mixes his labor with unowned land and a means of establishing private property rights in it and what is owned is limited to just that which has undergone this process. In the latter case, homesteading a square mile of land enables the owner of it to extend his property rights in a pyramid shaped form  from his holdings on the surface down into the core of the earth and up into the heavens, with no limit.
    Keywords: Homesteading;ad coelum;forestalling;property rights;views;slant drilling