Before revision: Work in this area has been happening for some years(see Reuter et al., (2005) Reuter, H.I., Giebel, A., Wendroth, O., 2005.
After revision: ,Work in this area has been happening for some years(see Reuter et al., (2005) Reuter, H.I., Giebel, A., Wendroth, O., 2005.