Amazon | Die Fluorescenz Des Lichtes (Classic Reprint) | Pisko, Franz Josef | Physics
3B Scientific Physics Teaching Aid - Diffuser Lens K, f = -500 mm - Part of the Optics System after Kröncke : Amazon.de: Stationery & Office Supplies
Sammellinsen in Physik | Schülerlexikon | Lernhelfer
3B Scientific Physics Teaching Aids - Collectable Lens K, f = +500 mm - Part of the Optics System after Kröncke : Amazon.de: Stationery & Office Supplies