TY - JOUR T1 - The high scholarly value of grey literature before and during Covid-19 JO - Scientometrics UR - http://dx.doi.org/10.1007/s11192-022-04398-3 PY - 2022/05/21 AU - Kousha K AU - Thelwall M AU - Bickley M ED - DO - DOI: 10.1007/s11192-022-04398-3 PB - Springer Science and Business Media LLC VL - 127 IS - 6 SP - 3489 EP - 3504 Y2 - 2024/09/19 ER -