The bibliographies to these works offer numerous other relevant sources.
Hand searching of the relevant journals and of the bibliographies of reviews was also performed.
A manual search of the bibliographies of relevant articles was also conducted.
No additional articles were found after screening the bibliographies of these articles.
Additionally, hand searches of the bibliographies of published systematic reviews and health technology assessments were performed.
The bibliographies of relevant articles were hand searched for other valuable references.
Additionally, the bibliographies of all selected articles were scrutinised for relevant articles.
We hand-searched the bibliographies of included studies and those of relevant review articles.
Additionally, the bibliographies of all relevant studies and review articles were searched.
Electronic searches were supplemented by hand searching the bibliographies of relevant articles.
The bibliographies of the retrieved literature were cross-referenced to identify other relevant studies.
