diff --git a/.travis.yml b/.travis.yml
index 28d4d10..608fbfc 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -5,6 +5,7 @@ os:
   - osx
 julia:
   - 1.0
+  - 1.1
   - nightly
 notifications:
   email: true
@@ -14,8 +15,6 @@ matrix:
     - julia: nightly
 
 script:
-  - julia -e 'using Pkg; pkg"add https://github.com/kalmarek/Groups.jl#enh/julia-v0.7"; Pkg.build(); Pkg.test(coverage=true);'
+  - julia -e 'using Pkg; pkg"add https://github.com/kalmarek/Groups.jl"; Pkg.build(); Pkg.test(coverage=true);'
 
-after_success:
-  # push coverage results to Coveralls
-   - julia -e 'import Pkg; Pkg.add("Coverage"); using Coverage; Codecov.submit(process_folder())'
+codecov: true
diff --git a/README.md b/README.md
index 4f40151..91389a5 100644
--- a/README.md
+++ b/README.md
@@ -1 +1,9 @@
 # GroupRings
+
+[![Build Status](https://travis-ci.org/kalmarek/GroupRings.jl.svg?branch=master)](https://travis-ci.org/kalmarek/GroupRings.jl)
+[![codecov](https://codecov.io/gh/kalmarek/GroupRings.jl/branch/master/graph/badge.svg)](https://codecov.io/gh/kalmarek/GroupRings.jl)
+
+Please have a look at [tests](https://github.com/kalmarek/GroupRings.jl/blob/master/test/runtests.jl) to see how to use this package. It depends on [AbstractAlgebra.jl](https://github.com/Nemocas/AbstractAlgebra.jl) and [Groups.jl](https://github.com/kalmarek/GroupRings.jl) 
+
+For an example applications have a look at our papers:
+[1703.09680](https://arxiv.org/abs/1703.09680), [1712.07167](https://arxiv.org/abs/1712.07167) and [1812.03456](https://arxiv.org/abs/1812.03456).
diff --git a/src/GroupRings.jl b/src/GroupRings.jl
index a29f7da..53f5156 100644
--- a/src/GroupRings.jl
+++ b/src/GroupRings.jl
@@ -301,11 +301,11 @@ function mul(a::T, X::GroupRingElem{S}) where {T<:Number, S<:Number}
    return GroupRingElem(a.*X.coeffs, parent(X))
 end
 
-(*)(a::Number, X::GroupRingElem) = mul(a,X)
-(*)(X::GroupRingElem, a::Number) = mul(a,X)
+(*)(a::Number, X::GroupRingElem) = mul(a, X)
+(*)(X::GroupRingElem, a::Number) = mul(a, X)
 
 # disallow Rings to hijack *(::, ::GroupRingElem)
-*(a::Union{AbstractFloat, Integer, RingElem, Rational}, X::GroupRingElem) = mul(a,X)
+*(a::Union{AbstractFloat, Integer, RingElem, Rational}, X::GroupRingElem) = mul(a, X)
 
 (/)(X::GroupRingElem, a) = 1/a*X
 (//)(X::GroupRingElem, a::Union{Integer, Rational}) = 1//a*X
@@ -375,10 +375,8 @@ function fmac!(result::AbstractVector{T},
 end
 
 @doc doc"""
-    GRmul!(result::AbstractVector{T},
-              X::AbstractVector,
-              Y::AbstractVector,
-             pm::Array{Int,2}) where {T<:Number}
+    GRmul!(result::AbstractVector{T}, X::AbstractVector, Y::AbstractVector,
+           pm::Matrix{<:Integer}) where {T<:Number}
 > The most specialised multiplication for `X` and `Y` (intended for `coeffs` of
 > `GroupRingElems`), using multiplication table `pm`.
 > Notes:
@@ -391,7 +389,7 @@ end
 function GRmul!(result::AbstractVector{T},
                    X::AbstractVector,
                    Y::AbstractVector,
-                  pm::Array{Int,2}) where {T<:Number}
+                  pm::AbstractMatrix{<:Integer}) where {T<:Number}
    z = zero(T)
    result .= z
 
@@ -399,9 +397,7 @@ function GRmul!(result::AbstractVector{T},
 end
 
 @doc doc"""
-    mul!{T}(result::GroupRingElem{T},
-                 X::GroupRingElem,
-                 Y::GroupRingElem)
+    mul!(result::GroupRingElem, X::GroupRingElem, Y::GroupRingElem)
 > In-place multiplication for `GroupRingElem`s `X` and `Y`.
 > `mul!` will make use the initialised entries of `pm` attribute of
 > `parent(X)::GroupRing` (if available), and will compute and store in `pm` the