update README.md.

Signed-off-by: sunfishfly <sunhuaifeng@sdu.edu.cn>

README.md

@@ -26,4 +26,6 @@ The authors recommend installing the latest version of the software.
 
 #### 如何引用 How to Cite
 
- The paper was submitted to  _Computers & Geosciences_  under the title "Efficient geophysical modeling techniques for complex geological structures".
+Minghong Liu, Huaifeng Sun, Rui Liu, Liqiang Hu, Ruijin Kong, Shangbin Liu*, 2024, Efficient geo-electromagnetic modeling techniques for complex geological structures: A karst MT example, Computers & Geosciences, Volume 185, 105557
+
+https://www.sciencedirect.com/science/article/pii/S0098300424000402?dgcid=coauthor#abs0015