Want to find scientific articles? Determine your information need first, then identify the aspects (concepts) you want to obtain information about.
In order to do so, define your subject in one sentence:
SUBJECT: Optimization models and methods for the winter maintenance of road networks
At times, the subject may be broader than the information need. It can also occur that the subject includes more than one information need.
It is important to differentiate between a subject and an information need. Here, the subject concerns the "Optimization models and methods for the winter maintenance of road networks".
This topic comprises two distinct information needs:
An information search should be conducted on one need at a time. The aspect dealing with the maintenance activities will be the one used in the subsequent steps of the search.