Publish from root project

I have multi project setup and want to be able to publish from my root project a number of artifacts from sub projects.

I have tried in my root project:

apply plugin :‘maven-publish’

publishing {
publications {
mavenJava (MavenPublication){
groupId 'blah’
artifactId ‘blah’
version ‘1.0.0’
artifact project (’:somesubprojecttypeeat’).configurations.archives.allartifacts
}
}
}

But get error when calling publish
’Cannot convert the provided notation to an object of type MavenArtifact’

I want to be able to do one publish that contains an ear and other artifacts from a subset of sub projects

Thanks
A