diff --git a/ChangeLog.md b/ChangeLog.md
index 1de4234..d65fe35 100644
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -1,8 +1,12 @@
-# Version 1.3.1 (not yet released)
+# Version 1.3.1 (released on: May 5, 2021)
 - New features:
     * Missing values are accepted if the input arrays have `eltype <:
       AbstractFloat`;
 
+    * Missing values are also accepted in calls to `hist`;
+
+	* VSCode and Pluto sessions are now properly handled (#35 and #43);
+
 - Bugfix:
 	* Multiplot were not displayed in Jupyter (#25);
 
diff --git a/README.md b/README.md
index c184a68..d25fc37 100644
--- a/README.md
+++ b/README.md
@@ -3,7 +3,7 @@
 
 [![Build Status](https://travis-ci.org/gcalderone/Gnuplot.jl.svg?branch=master)](https://travis-ci.org/gcalderone/Gnuplot.jl)
 [![License](http://img.shields.io/badge/license-MIT-brightgreen.svg?style=flat)](LICENSE.md)
-[![DocumentationStatus](https://img.shields.io/badge/docs-stable-blue.svg?style=flat)](https://gcalderone.github.io/Gnuplot.jl/v1.3.0/)
+[![DocumentationStatus](https://img.shields.io/badge/docs-stable-blue.svg?style=flat)](https://gcalderone.github.io/Gnuplot.jl/v1.3.1/)
 
 
 **Gnuplot.jl** is a simple package able to send both data and commands from Julia to an underlying [gnuplot](http://gnuplot.sourceforge.net/) process.  Its main purpose it to provide a fast and powerful data visualization framework, using an extremely concise Julia syntax. It also has automatic display of plots in Jupyter, Juno and VS Code.
@@ -21,9 +21,9 @@ You may check the installed **Gnuplot.jl** version with:
 ```julia
 ]st Gnuplot
 ```
-If the displayed version is not v1.3.0 you are probably having a dependency conflict. In this case try forcing installation of the latest version with:
+If the displayed version is not v1.3.1 you are probably having a dependency conflict. In this case try forcing installation of the latest version with:
 ```julia
-]add Gnuplot@1.3.0
+]add Gnuplot@1.3.1
 ```
 and check which package is causing the conflict.
 
@@ -37,7 +37,7 @@ test_terminal()
 
 
 ## Quick start
-The following examples are supposed to be self-explaining.  See [documentation](https://gcalderone.github.io/Gnuplot.jl/v1.3.0/) for further informations.
+The following examples are supposed to be self-explaining.  See [documentation](https://gcalderone.github.io/Gnuplot.jl/v1.3.1/) for further informations.
 
 ### A simple parabola
 ```julia
diff --git a/docs/src/install.md b/docs/src/install.md
index 66b8583..8ab5494 100644
--- a/docs/src/install.md
+++ b/docs/src/install.md
@@ -19,11 +19,11 @@ Check **Gnuplot.jl** version with:
 ```julia-repl
 julia> ]st Gnuplot
 Status `~/.julia/environments/v1.4/Project.toml`
-  [dc211083] Gnuplot v1.3.0
+  [dc211083] Gnuplot v1.3.1
 ```
-If the displayed version is not `v1.3.0` you are probably having a dependency conflict.  In this case try forcing installation of the latest version with:
+If the displayed version is not `v1.3.1` you are probably having a dependency conflict.  In this case try forcing installation of the latest version with:
 ```julia-repl
-julia> ]add Gnuplot@1.3.0
+julia> ]add Gnuplot@1.3.1
 ```
 and check which package is causing the conflict.
 
diff --git a/docs/src/recipes.md b/docs/src/recipes.md
index 8091225..daa918b 100644
--- a/docs/src/recipes.md
+++ b/docs/src/recipes.md
@@ -125,7 +125,7 @@ end
 with only one mandatory argument.  In order to exploit the optional keyword we can explicitly invoke the recipe as follows:
 ```@example abc
 img = testimage("walkbridge");
-@gp palette(:gray) recipe(img, "flipy rot=15deg")
+@gp palette(:gray1) recipe(img, "flipy rot=15deg")
 saveas("recipes007c") # hide
 ```
 ![](assets/recipes007c.png)
diff --git a/docs/src/style.md b/docs/src/style.md
index f14686f..91e9385 100644
--- a/docs/src/style.md
+++ b/docs/src/style.md
@@ -1,6 +1,6 @@
 # Style Guide
 
-The **Gnuplot.jl** loose syntax allows to create a plot using very different approaches.  While this was one of the initial purposes for the package, it may lead to decreased code readability if not used judiciously.
+The **Gnuplot.jl** loose syntax allows to create a plot using very different approaches.  While this was one of the initial purposes for the package, it may lead to a reduced code readability if not used judiciously.
 
 Here I will summarize a few, non-mandatory, guidelines which allows to maintain a neat syntax and a high readability:
 
diff --git a/docs/src/terminals.md b/docs/src/terminals.md
index 693f87e..875cd50 100644
--- a/docs/src/terminals.md
+++ b/docs/src/terminals.md
@@ -4,11 +4,7 @@ Gnuplot provides dozens of terminals to display plots or export them into files
 
 To use a specific terminal for interactive use you may either set it as initialization command for all new session with (see [Options](@ref)):
 ```julia
-Gnuplot.options.term = "wxt")
-```
-or directly send the command to a specific session (see [Direct command execution](@ref))
-```julia
-gpexec("set term wxt")
+Gnuplot.options.term = "wxt"
 ```
 See official [gnuplot documentation](http://gnuplot.sourceforge.net/documentation.html) for further info on terminals and their options.
 
@@ -16,13 +12,13 @@ See official [gnuplot documentation](http://gnuplot.sourceforge.net/documentatio
 ## Interactive terminals (`wxt` and `qt`)
 The multiplatform `wxt` and `qt` terminals are among the most widely used ones for their nicely looking outputs on display and for their interactive capabilities.
 
-You may set them as terminal with:
+You may use such terminals with:
 ```
-"set term wxt size 800,600"
+Gnuplot.options.term = "wxt size 800,600"
 ```
 or
 ```
-"set term qt  size 800,600"
+Gnuplot.options.term = "qt  size 800,600"
 ```
 (the `size 800,600` is optional and can be omitted).
 
@@ -58,7 +54,7 @@ Gnuplot is also able to export vector (i.e. non-raster) plots through the `svg`
 The `cairolatex` terminal allows to produce high quality plots by splitting the output into a PDF file (containing a rasterized image of a plot) and a `.tex` file (containing all the text as ``\LaTeX`` code).  The following example shows how to write plot tics and an equation in ``\LaTeX``:
 ```julia
 x = LinRange(-2pi, 2pi, 1000)
-@gp t="Polynomial approximation of sin(x)"  "set style fill transparent solid 0.6 noborder"
+@gp tit="Polynomial approximation of sin(x)"  "set style fill transparent solid 0.6 noborder"
 @gp :- raw"""set xtics ('$-\pi$' -pi, '$-\pi/2$' -pi/2, 0, '$\pi/2$' pi/2, '$\pi$' pi)"""
 @gp :- xr=3.8.*[-1, 1] yr=[-1.5,1.5] key="box opaque left horiz" linetypes(:Blues_3) "set grid front"
 latex = raw"""\begin{minipage}[c]{\textwidth}\begin{equation*}""" *