![File:Kees Zwaan en Hans Rosenberg - Bibliotheek Sterrewacht Sonnenborgh, Utrecht, 1967.jpg - Wikimedia Commons File:Kees Zwaan en Hans Rosenberg - Bibliotheek Sterrewacht Sonnenborgh, Utrecht, 1967.jpg - Wikimedia Commons](https://upload.wikimedia.org/wikipedia/commons/9/96/Kees_Zwaan_en_Hans_Rosenberg_-_Bibliotheek_Sterrewacht_Sonnenborgh%2C_Utrecht%2C_1967.jpg)
File:Kees Zwaan en Hans Rosenberg - Bibliotheek Sterrewacht Sonnenborgh, Utrecht, 1967.jpg - Wikimedia Commons
![File:Chrysler Viper GTS-R - Val Hillebrand & Rob van der Zwaan at Mcleans at the 2004 FIA GT Championship, Donington (50935688171).jpg - Wikimedia Commons File:Chrysler Viper GTS-R - Val Hillebrand & Rob van der Zwaan at Mcleans at the 2004 FIA GT Championship, Donington (50935688171).jpg - Wikimedia Commons](https://upload.wikimedia.org/wikipedia/commons/b/b9/Chrysler_Viper_GTS-R_-_Val_Hillebrand_%26_Rob_van_der_Zwaan_at_Mcleans_at_the_2004_FIA_GT_Championship%2C_Donington_%2850935688171%29.jpg)
File:Chrysler Viper GTS-R - Val Hillebrand & Rob van der Zwaan at Mcleans at the 2004 FIA GT Championship, Donington (50935688171).jpg - Wikimedia Commons
![File:Chrysler Viper GTS-R - Val Hillebrand & Rob van der Zwaan and Saleen S7-R - Michael Bartels & Uwe Alzen at Mcleans at the 2004 FIA GT Championship, Donington (50934999498).jpg - Wikimedia File:Chrysler Viper GTS-R - Val Hillebrand & Rob van der Zwaan and Saleen S7-R - Michael Bartels & Uwe Alzen at Mcleans at the 2004 FIA GT Championship, Donington (50934999498).jpg - Wikimedia](https://upload.wikimedia.org/wikipedia/commons/d/da/Chrysler_Viper_GTS-R_-_Val_Hillebrand_%26_Rob_van_der_Zwaan_and_Saleen_S7-R_-_Michael_Bartels_%26_Uwe_Alzen_at_Mcleans_at_the_2004_FIA_GT_Championship%2C_Donington_%2850934999498%29.jpg)