Occurrence of Attributes in Original Text

The text related to the cultural heritage 'Memphis and its Necropolis – the Pyramid Fields from Giza to Dahshur' has mentioned 'World Heritage' in the following places:
Occurrence Sentence Text Source
Along with the pyramid complex at Giza, they have been preserved as a World Heritage Site since 1979.
Despite the efforts for protection and requirements to retain its World Heritage status, a comprehensive management plan for the overall property has not been formulated.
This needs to be submitted to the World Heritage Committee.