• https://theses.ubn.ru.nl/items/fff82955-9870-4bb9-81a8-26b7fc6e8072
• https://theses.ubn.ru.nl/items/fff97517-7acf-4310-be2f-f7f7d9336614
• https://theses.ubn.ru.nl/items/fffa6648-49c7-43b0-9193-09b71744c568
• https://theses.ubn.ru.nl/items/fffa89f6-84bf-4ed6-9e7a-05ed47f11aa0
• https://theses.ubn.ru.nl/items/fffb93bf-0b5e-48b9-bf3f-aa678eeffbbd
• https://theses.ubn.ru.nl/items/fffbc494-a61d-4d27-b19a-c7b1afae6c33
• https://theses.ubn.ru.nl/items/fffddbdd-0de5-4220-84c1-1faf49b2a4b3