ДИМИТРОВ, Н., Системен подход към критичната инфраструктура. 2019, Варна: ВВМУ "Н. Й. Вапцаров". ISSN 978-619-7428-40-7
НИКОЛОВ, Ж. Някои аспекти на киберсигурността на критичната инфраструктура в крайбрежната зона. Известия на Съюза на учените – Варна, серия „Морски науки”. Варна: Съюз на учените – Варна, 2019, 3-6. ISSN 1314-3379
КАРАДЕНЧЕВА, А. Хуманитарната криза като една от най-тежките за човечеството ситуации. е-JOURNAL VFU, Варненски свободен унивeрситет "Черноризец Храбър". Варна, 2020, 13. ISSN 1313-7514. [Accessed 29 October 2021]. Available from: https://ejournal.vfu.bg/bg/politicheski_nauki.html.
A New cruise ships for 2021 [online]. 2021 [Accessed 29 October 2021]. Available from: https://www.bolsovercruiseclub.com/new-ships/
BAILEY, J., Boudicca & Black Watch Are Heading To Turkey. 2020. University of Delaware. [Accessed 29 October 2021]. Available from: https://www.cruisecapital.co.uk/boudicca-black-watch-are-heading-to-turkey/
BULLOCK, С., German rail service sees upward trend as travel returns [online]. 2021 [Accessed 29 October 2021]. Available from: https://www.itij.com/latest/news/german-rail-service-sees-upward-trend-travel-returns#article-author-0
BULLOCK, С., Third of Brits want to go abroad this summer[online]. 2021 [Accessed 29 October 2021]. Available from: https://www.itij.com/latest/news/third-brits-want-go-abroad-summer
BULLOCK, С., US travellers keen to go on adventure trips [online]. 2021 [Accessed 29 October 2021]. Available from: https://www.itij.com/latest/news/us-travellers-keen-go-adventure-trips
CLIA, Europe Market Report 2018.Washington, 2019
CLIA, Cruise trends & industry outlook 2019, Washington, 2020
CLIA, The Economic Contribution of the International Cruise Industry Globally in 2019. Washington, 2020
CLIA, Global Passenger Report 2020. Washington, 2021
CLIA, 2021 State of the Cruise Industry. Washington, 2021
CLIA welcomes the restart of international cruise [online]. 2021 [Accessed 29 October 2021]. Available from https://cruising.org/en-gb/news-and-research/press-room/2021/july/clia-welcomes-the-restart-of-international-cruise
FCCA, Cruise Industry Overview 2018, Florida, 2019
GOLLAN, D., Where are all the cruise ships? [online]. 2021 [Accessed 29 October 2021]. Available from: https://www.forbes.com/sites/douggollan/2020/08/10/where-are-all-the-cruise-ships/
KORCOK, M., International cruise industry restarts [online]. 2021 [Accessed 29 October 2021]. Available from: https://www.itij.com/latest/long-read/international-cruise-industry-restarts
SMITH, E., Royal Caribbean announces full return by 2022 [online]. [Accessed 29 October 2021]. Available from: https://www.cruise118.com/news/royal-caribbean-announces-full-restart-plans/
SMITH, E., Summer 2021 UK Coastal Cruises [online]. 2021 [Accessed 29 October 2021]. Available from: https://www.cruise118.com/news/summer-2021-uk-coastal-cruises/
