Morphology, published by Springer, is one of the only academic journals that is dedicated specifically to morphology. The articles appearing in this journal cover theoretical issues and in-depth descriptions of under-researched languages as well as of linguistic variation. They are generally quite advanced, however. Another specialized journal is Word Structure, published by Edinburgh University Press.
The World Atlas of Language Structures Online, published by the Max Planck Institute for Evolutionary Anthropology, is a sizable database with discussions –and pretty maps!– of a variety of linguistic phenomena. The content is, on the whole, relatively accessible. The following chapters are especially relevant here:
Chapters 20, 21 and 22 for a critique of morphological types and the criteria behind the classification;
Chapters 35, 39, 44 and 45 about the distinctions that languages make in their personal pronouns;
Chapters 37, 38 and 41 about articles and demonstratives.
For more information about how we gloss examples from languages other than English, check out the Leipzig Glossing Rules. This webpage also features a list of the abbreviations most commonly used in glossing.
Some other interesting articles available online are the following:
Croft (2020) for an attempt to capture word classes across languages;
Haspelmath (2017) on the problems with defining the notion of word in the world’s languages;
Johnston (2006) for a short and accessible introduction to the morphology of sign languages.