Update references in magnetic_decapot_grid.py

examples/MagneticMiliPedeGrid/magnetic_decapot_grid.py

@@ -112,12 +112,14 @@ class MagneticDecapotSimualtor(
     volume = base_area * base_length_magnetic_rods
     moment_of_inertia = np.pi / 4 * base_radius_magnetic_rod**4
 
-    # Parameters are from Gu2020
+    # Parameters are from
+    # Gu, Hongri, et al. "Magnetic cilia carpets with programmable metachronal waves." Nature communications 11.1 (2020).
     angular_frequency = np.deg2rad(
         5.0
     )  # angular frequency of the rotating magnetic field
     magnetic_field_strength = 80e-3  # 80mT
-    # MBAL2_EI is a non-dimensional number from Wang 2019
+    # MBAL2_EI is a non-dimensional number from
+    # Wang, Liu, et al. "Hard-magnetic elastica." Journal of the Mechanics and Physics of Solids 142 (2020).
     MBAL2_EI = (
         3.82e-5 * magnetic_field_strength * 4e-3 / (1.85e5 * np.pi / 4 * (0.4e-3) ** 4)
     )  # Magnetization magnitude * B * Length/(EI)