TY - JOUR AU - Kristoffersen PY - 2020 DA - 2020// TI - Hospital-based headache care during the Covid-19 pandemic in Denmark and Norway JO - J Headache Pain VL - 21 UR - https://doi.org/10.1186/s10194-020-01195-2 DO - 10.1186/s10194-020-01195-2 ID - Kristoffersen2020 ER -