diff --git a/src/models/unobserved_components.jl b/src/models/unobserved_components.jl
index 36420e5..172fe31 100644
--- a/src/models/unobserved_components.jl
+++ b/src/models/unobserved_components.jl
@@ -165,7 +165,7 @@ string: `"local linear trend"`
 ```math
 \begin{gather*}
     \begin{aligned}
-        y_{t} &=  \mu_{t} + \gamma_{t} + \varepsilon_{t} \quad &\varepsilon_{t} \sim \mathcal{N}(0, \sigma^2_{\varepsilon})\\
+        y_{t} &=  \mu_{t} + \varepsilon_{t} \quad &\varepsilon_{t} \sim \mathcal{N}(0, \sigma^2_{\varepsilon})\\
         \mu_{t+1} &= \mu_{t} + \nu_{t} + \xi_{t} \quad &\xi_{t} \sim \mathcal{N}(0, \sigma^2_{\xi})\\
         \nu_{t+1} &= \nu_{t} + \zeta_{t} \quad &\zeta_{t} \sim \mathcal{N}(0, \sigma^2_{\zeta})\\
     \end{aligned}
@@ -177,7 +177,7 @@ string: `"smooth trend"`
 ```math
 \begin{gather*}
     \begin{aligned}
-        y_{t} &=  \mu_{t} + \gamma_{t} + \varepsilon_{t} \quad &\varepsilon_{t} \sim \mathcal{N}(0, \sigma^2_{\varepsilon})\\
+        y_{t} &=  \mu_{t} + \varepsilon_{t} \quad &\varepsilon_{t} \sim \mathcal{N}(0, \sigma^2_{\varepsilon})\\
         \mu_{t+1} &= \mu_{t} + \nu_{t}\\
         \nu_{t+1} &= \nu_{t} + \zeta_{t} \quad &\zeta_{t} \sim \mathcal{N}(0, \sigma^2_{\zeta})\\
     \end{aligned}