Dekkers, N. H. (1969). Correction of spherical aberration.
Lua i Stíl Chicago (17ú heag.)Dekkers, Nicolaas Henricus. Correction of Spherical Aberration. 1969.
Lua MLA (8ú heag.)Dekkers, Nicolaas Henricus. Correction of Spherical Aberration. 1969.
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