Update README.md

README.md

@@ -17,6 +17,7 @@ or:
 Quadcubic interpolation of 4D gridded data. Paper to follow about this.
 Takes in gridded data from comma-separated input file, either a scalar field U as an N x 5 (x,y,z,t,U) array or a vector field B as an N x 7 (x, y, z, t, Bx, By, Bz) array.
 
+Background and 4D method see: https://arxiv.org/abs/1904.09869
 
 Package Dependencies
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