These need to be included. While one is never sure that ALL pertinent records have been found, we have to try to exhaust all reasonable possibilities for omissions. Often we have missed records because we have failed to use all forms of a particular search term, e.g. we searched snake but forgot snakes, or we searched pesticides but forgot herbicides. Expand is your access to the Indexing Terms Dictionary. This alphabetical list will give you alternative forms of the terms that you have been using and may suggest others.
Truncation is a shortcut method of covering a series of terms with one term.
Selecting a series of numbered e-sets from an Expand statement is another way of doing this. For records that are relevant to your topic, the list of IT's and ST's may well suggest other terms that need to be added to your refined strategy . Recall that IT's and ST's are given when the display format ALL is used. This assignment is to be performed entirely in the LCA learning file . You must have missed them.