Add punctuation: The product can be labelled either by application of a label on the product itself or by a reference in the product documentation
A: The product can be labelled either by application of a label on the product itself or by a reference in the product documentation.

Add punctuation: One can easily play slots what makes them so popular
A: One can easily play slots what makes them so popular.

Add punctuation: Cooperation has been initiated with relevant partners on preparing environmental product declarations for consumers and producers alike
A:
Cooperation has been initiated with relevant partners on preparing environmental product declarations for consumers and producers alike.