Dalen, D. v. (1963). Extension problems in intuitionistic plane projective geometry. Drukkerij Holland.
Lua i Stíl Chicago (17ú heag.)Dalen, D. van. Extension Problems in Intuitionistic Plane Projective Geometry. Amsterdam: Drukkerij Holland, 1963.
Lua MLA (8ú heag.)Dalen, D. van. Extension Problems in Intuitionistic Plane Projective Geometry. Drukkerij Holland, 1963.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.