To cite gapfill in publications use:
Gerber F, de Jong R, Schaepman ME, Schaepman-Strub G, Furrer R (2018). “Predicting Missing Values in Spatio-Temporal Remote Sensing Data.” IEEE Transactions on Geoscience and Remote Sensing, 1–13. doi:10.1109/TGRS.2017.2785240, https://doi.org/10.1109/TGRS.2017.2785240.
Corresponding BibTeX entry:
@Article{, title = {Predicting Missing Values in Spatio-Temporal Remote Sensing Data}, author = {Florian Gerber and Rogier {de Jong} and Micheal E. Schaepman and Gabriela Schaepman-Strub and Reinhard Furrer}, journal = {IEEE Transactions on Geoscience and Remote Sensing}, year = {2018}, pages = {1--13}, url = {https://doi.org/10.1109/TGRS.2017.2785240}, doi = {10.1109/TGRS.2017.2785240}, }