File:Heike Kamerlingh Onnes - 32 - Workshop K with student instrument makers ("blue boys") and instrument maker Curvers, 1900 Physics laboratory (Natuurkundig Laboratorium), Steenschuur, Leiden.png
Heike_Kamerlingh_Onnes_-_32_-_Workshop_K_with_student_instrument_makers_("blue_boys")_and_instrument_maker_Curvers,_1900_Physics_laboratory_(Natuurkundig_Laboratorium),_Steenschuur,_Leiden.png (400 × 291 pixels, file size: 85 KB, MIME type: image/png)