G.M.T. Trienekens, Tussen ons volk en de honger. De voedselvoorziening 1940-1945, Utrecht, 1985, pp 9-18.
 E.g. Haarlems Dagblad, ‘De installaties voor de centrale keukens in aanbouw’, 5-12-1940.
 Trienekens, 1985, p. 2.
 The threat of war from the East had increased since the election of Adolf Hitler as Chancellor. At the end of the 1930s, the Netherlands made rapid efforts to increase its stockpile of arms and ammunition.
 This was the shortened name of the Ministeriële Commissie voor Defensie-aangelegenheden, or ministerial commission for defence matters, presided over by prime minister H. Colijn. The other members of the commission were the ministers of defence, economic affairs and finance, plus Groothoff, Louwes and Teppema. Trienekens, p. 12.
 DHV 25 jaar, 1942, p. 130.
 See James C. Kennedy, Een beknopte geschiedenis van Nederland, Amsterdam, 2017, pp. 316-317 and A.M.A. Goossens, Het Staatsbedrijf der Artillerie Inrichtingen, Version C, Dec 2007.
 The anniversary book of 1942 makes specific mention of the economic significance of this major order in times of crisis: the construction sum totalled 2 million guilders. DHV 25 jaar, 1942, p. 130.
 Hein A. M. Klemann, ‘Economie en totale oorlog’, BMGN, 119 (2004) ep. 4, 577-581, p. 580.
 Most companies decided to a greater or lesser extent on the former. According to Jan Luiten van Zanden, Een klein land in de 20e eeuw. Economische geschiedenis van Nederland 1914-1995, Utrecht, 1997, pp 166-167 and Tessel Polman, Van Waterstaat tot Wederopbouw. Het leven van dr. ir. J.A. Ringers (1885-1965), pp 186-187 and 211-218.
 National Archives, The Hague, Rijksbureau Voorbereiding Voedselvoorziening in Oorlogstijd, access number 2.11.23.01, record number 119 Massavoeding door Centrale Keukens, 1940.
 The vitally important economic role which Groothoff played for the agency has never previously been a subject of investigation. What is clear however, is that DHV held Arnold Groothoff in high regard: the 1942 anniversary book was dedicated to “A. Groothoff who initiated the firm’s founding in 1916”.
 Meanwhile, the firm’s other work continued under the auspices of Technisch Adviesbureau (TAB) and, according to the records, also as Ingenieurs- en adviesbureau DHV.
 ‘Ook Schiedam krijgt een volkskeuken’, Rotterdamsch nieuwsblad, 17 December 1940.
 DHV 25 jaar, 1942, p. 137.
 The need to “tackle the problem of condensation in the kitchens” had become apparent. NL-HaNA, Voedselvoorziening/Massavoeding, 2.11.30.06, record no. 45 Verslag afdeeling Centrale Keukens, date 15 February 1941.
 There are conflicting reports in source material about the standardisation of kitchen capacity. DHV talked about 3,000 and 6,000 persons (that is, food portions). Newspapers wrote about 4,000 and 6,000.
 Pumice concrete is a low-density concrete made from a mixture of pumice aggregate, water and cement. https://www.joostdevree.nl/shtmls/bims.shtml As it happened, during the war – owing to shortages of materials – timber once again became the standard option. See e.g. DHV 1942, p 138 and archive images.
 ‘The community kitchen in Arnhem-noord’, Arnhemsche Courant, 21 January 1941.
 The original Dutch plan for the kitchens – meals for the less well-off – ended in the second year of the war. The Germans wanted to use the kitchens primarily for feeding or replenishing workers who contributed to maintaining their war efforts. Trienekens, 1985, pp. 210-214.
 DHV 25 jaar, 1942, p 138.
 DHV 25 jaar, 1942, p 28.
 In 1942 DHV had around 37 employees [on its books]. Grandson Herbert Verhey explained that several new members of staff joined the company during the war: at least 3 recent graduates from the Delft school of engineering were added to the firm’s payroll. Source: interview with H. Verhey, 3 Dec. 2020.
 NL-HaNa, Militair Gezag, 2.13.25, record no. 247 In February 1944, the Rijksbureau Voedselvoorziening was operating 173 kitchens and two motorised railway kitchens.
 One tragic exception to this was draughtsman Mozes Manheim. He was a highly respected Jewish employee who had been there from the very beginning and went into retirement on 3 June 1942. Manheim was arrested in a raid in Amsterdam and taken to the Sobibor death camp via Westerbork, the Nazi’s transit camp in the Netherlands. He was murdered in Sobibor in 1943. Jetje Manheim, Mijn grootouders, unpublished manuscript, pp 87- 115.
 Royal HaskoningDHV company archives, Heederik Speech, 1 June 1945.