Hippisley-Cox, J., Patone, M., Mei, X., Saatci, D., Dixon, S., Khunti, K., Zaccardi, F., Watkinson, P., Shankar-Hari, M., Doidge, J., Harrison, D., Griffin, S., Sheikh, A. & Coupland, C. 2021, 'Risk of thrombocytopenia and thromboembolism after covid-19 vaccination and SARS-CoV-2 positive testing: self-controlled case series study', The BMJ, 374(8304), article no: n1931. https://doi.org/10.1136/bmj.n1931