diff --git a/README.md b/README.md
index b05111810..095a164f5 100644
--- a/README.md
+++ b/README.md
@@ -73,7 +73,7 @@ P = K/(s*((J*s + b)*(L*s + R) + K^2))
 #Continuous-time transfer function model
 
 # Create an array of closed loop systems for different values of Kp
-CLs = TransferFunction[kp*P/(1 + kp*P) for kp = [1, 5, 15]];
+CLs = [kp*P/(1 + kp*P) for kp ∈ [1, 5, 15]];
 
 # Plot the step response of the controllers
 # Any keyword arguments supported in Plots.jl can be supplied
diff --git a/lib/ControlSystemsBase/Project.toml b/lib/ControlSystemsBase/Project.toml
index ce533754c..f7f44c303 100644
--- a/lib/ControlSystemsBase/Project.toml
+++ b/lib/ControlSystemsBase/Project.toml
@@ -7,8 +7,6 @@ version = "1.13.2"
 [deps]
 DSP = "717857b8-e6f2-59f4-9121-6e50c889abd2"
 ForwardDiff = "f6369f11-7733-5829-9624-2563aa707210"
-IterTools = "c8e1da08-722c-5040-9ed9-7db0dc04731e"
-LaTeXStrings = "b964fa9f-0449-5b57-a5c2-d3ea65f4040f"
 LinearAlgebra = "37e2e46d-f89d-539d-b4ee-838fcccc9c8e"
 MacroTools = "1914dd2f-81c6-5fcd-8719-6d5c9610ff09"
 MatrixEquations = "99c1a7ee-ab34-5fd5-8076-27c950a045f4"
@@ -18,7 +16,6 @@ PrecompileTools = "aea7be01-6a6a-4083-8856-8a6e6704d82a"
 Printf = "de0858da-6303-5e67-8744-51eddeeeb8d7"
 Random = "9a3f8284-a2c9-5f02-9a11-845980a1fd5c"
 RecipesBase = "3cdcf5f2-1ef4-517c-9805-6587b60abb01"
-SparseArrays = "2f01184e-e22b-5df5-ae63-d93ebab69eaf"
 StaticArraysCore = "1e83bf80-4336-4d27-bf5d-d5a4f845583c"
 UUIDs = "cf7118a7-6976-5b1a-9a39-7adc72f591a4"
 
@@ -34,8 +31,6 @@ Aqua = "0.5"
 DSP = "0.6.1, 0.7, 0.8"
 ForwardDiff = "0.10"
 ImplicitDifferentiation = "0.4.2"
-IterTools = "1.0"
-LaTeXStrings = "1.0"
 LinearAlgebra = "<0.0.1, 1"
 MacroTools = "0.5"
 MatrixEquations = "1, 2.1"
@@ -45,7 +40,6 @@ PrecompileTools = "1"
 Printf = "<0.0.1, 1"
 Random = "<0.0.1, 1"
 RecipesBase = "1"
-SparseArrays = "<0.0.1, 1"
 StaticArraysCore = "1"
 UUIDs = "<0.0.1, 1"
 julia = "1.6"
@@ -58,8 +52,9 @@ FiniteDifferences = "26cc04aa-876d-5657-8c51-4c34ba976000"
 GR = "28b8d3ca-fb5f-59d9-8090-bfdbd6d07a71"
 ImplicitDifferentiation = "57b37032-215b-411a-8a7c-41a003a55207"
 Plots = "91a5bcdd-55d7-5caf-9e0b-520d859cae80"
+SparseArrays = "2f01184e-e22b-5df5-ae63-d93ebab69eaf"
 StaticArrays = "90137ffa-7385-5640-81b9-e52037218182"
 Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
 
 [targets]
-test = ["Test", "Aqua", "ComponentArrays", "Documenter", "FiniteDifferences", "ImplicitDifferentiation", "GR", "Plots", "StaticArrays"]
+test = ["Test", "Aqua", "ComponentArrays", "Documenter", "FiniteDifferences", "ImplicitDifferentiation", "GR", "Plots", "SparseArrays", "StaticArrays"]
diff --git a/lib/ControlSystemsBase/src/ControlSystemsBase.jl b/lib/ControlSystemsBase/src/ControlSystemsBase.jl
index 60d25b9a6..9aefb2983 100644
--- a/lib/ControlSystemsBase/src/ControlSystemsBase.jl
+++ b/lib/ControlSystemsBase/src/ControlSystemsBase.jl
@@ -126,8 +126,7 @@ export  LTISystem,
         add_output
 
 
-# QUESTION: are these used? LaTeXStrings, Requires, IterTools
-using RecipesBase, LaTeXStrings, LinearAlgebra
+using RecipesBase, LinearAlgebra
 import Polynomials
 import Polynomials: Polynomial, coeffs
 import Base: +, -, *, /, (==), (!=), isapprox, convert, promote_op
diff --git a/lib/ControlSystemsBase/src/pid_design.jl b/lib/ControlSystemsBase/src/pid_design.jl
index 2f4238cf3..0f8396dbc 100644
--- a/lib/ControlSystemsBase/src/pid_design.jl
+++ b/lib/ControlSystemsBase/src/pid_design.jl
@@ -251,7 +251,7 @@ function pidplots(P::LTISystem, args...;
         kp = kps[i]
         ki = kis[i]
         kd = kds[i]
-        label = latexstring("k_p = $(round(kp, digits=3)),      k_i = $(round(ki, digits=3)),      k_d = $(round(kd, digits=3))")
+        label = "\$k_p = $(round(kp, digits=3)),      k_i = $(round(ki, digits=3)),      k_d = $(round(kd, digits=3))\$"
 
         C = pid(kp,ki,kd,form=form)
         T = robust_minreal(feedback(P*C, 1))
@@ -384,7 +384,7 @@ function stabregionPID(P, ω = _default_freq_vector(P,Val{:bode}()); kd=0, form=
     K   = convert_pidparams_from_parallel.(kp, ki, kd, form)
     kp, ki = getindex.(K, 1), getindex.(K, 2)
     fig = if doplot
-        RecipesBase.plot(kp,ki,linewidth = 1.5, xlabel=L"k_p", ylabel=L"k_i", title="Stability region of P, k_d = $(round(kd, digits=4))")
+        RecipesBase.plot(kp,ki,linewidth = 1.5, xlabel="\$k_p\$", ylabel="\$k_i\$", title="Stability region of P, k_d = $(round(kd, digits=4))")
     else 
         nothing
     end
@@ -401,7 +401,7 @@ function stabregionPID(P::Function, ω = exp10.(range(-3, stop=1, length=50)); k
     K       = convert_pidparams_from_parallel.(kp, ki, kd, form)
     kp, ki  = getindex.(K, 1), getindex.(K, 2)
     fig = if doplot
-        RecipesBase.plot(kp,ki,linewidth = 1.5, xlabel=L"k_p", ylabel=L"k_i", title="Stability region of P, k_d = $(round(kd, digits=4))")
+        RecipesBase.plot(kp,ki,linewidth = 1.5, xlabel="\$k_p\$", ylabel="\$k_i\$", title="Stability region of P, k_d = $(round(kd, digits=4))")
     else 
         nothing
     end
diff --git a/lib/ControlSystemsBase/src/plotting.jl b/lib/ControlSystemsBase/src/plotting.jl
index e9207585d..6a18ddfd0 100644
--- a/lib/ControlSystemsBase/src/plotting.jl
+++ b/lib/ControlSystemsBase/src/plotting.jl
@@ -90,7 +90,7 @@ end
 #         minor     = minor[ind]
 #         minorText = minorText[ind]
 #         if length(minor) > minor_text_limit
-#             minorText = [" " for t in minorText]#fill!(minorText, L" ")
+#             minorText = [" " for t in minorText]#fill!(minorText, " ")
 #         end
 #         perm = sortperm([major; minor])
 #         return [major; minor][perm], [majorText; minorText][perm]