In general, "alert services" refer to services or features included with scholarly databases that send you email notifications when something of interest to you has been published or added to a database. These can be on specific topics or from specific journals. Listed below are multidisciplinary content alert services that notify you when a new issue of a journal is published. Descriptions of resources are adapted or quoted from vendor websites.
Citation tracking is a way to trace the scholarly impact of a specific research study or author's work. It can be an effective way to use a "landmark" or influential article to find more recent, related articles that cite that article. It also can be an effective way to track who has subsequently cited the work of a leading scholar in a particular field.