This is the 15398th most frequent Russian word.
правительственного
"Правительственного" means "governmental" or "related to the government."
Here, "правительственного" is used as an adjective describing "research," indicating that the study is conducted or sponsored by the government.
Этот отчет составлен на основе правительственного исследования.
This report is based on a government study.
In this sentence, "правительственная" attributes the nature of a press conference as being associated with the government, emphasizing its origin or organization.
Вчера состоялась правительственная пресс-конференция.
Yesterday, a government press conference took place.
Here, "правительственной" describes a position, indicating that the role is within or related to governmental institutions.