I have figure with multiple figures (top, bottom). The journal that I want to send my paper to require that we use (a,b,..) for multiple figures. I followed that but since all my figures have titles on, I felt that putting caption for (a) and (b) is not necessary. Can I leave the caption empty ? The second question if I use a,b for figures, in the test when I refer to figure 1 (a), it shows as Figure 1a How should this looks in paper ?