A good complementary method to find relevant literature is to start from one good publication. It could be that you have found one relevant paper but are having trouble finding much else. Starting with this publication, you can either look in the reference list to look at the cited publications, or use a database that register citations to find out which newer publications have cited your chosen publication.
Reviews in particular are useful to start from since they have a long reference list but are also often cited a lot.
|Web of Science|
|When you click on a result (i.e. viewing a database record) you can in the right hand margin find a heading called "Citation Network". Here you will find quick links to both references in the article ("Cited references") as well as newer publications that have cited the paper ("Times cited").|
|Under each search result in the result list there is a link called "Cited by...". If you follow this link you will get a new result list with the publications that have cited the paper.|
|When you click on a result, you can in the right hand margin find which publications that have cited the article in question ("Cited by"). If you scroll down the page you will find the references.|