@book{Ayers+2017,
url = {https://doi.org/},
title = {The German Ocean},
title = {Medieval Europe around the North Sea},
author = {Brian Ayers},
publisher = {Equinox Publishing},
address = {},
doi = {doi:},
isbn = {9781781794401},
year = {2017},
lastchecked = {2017}
}