Penn State's Center for Language Acquisition has established a searchable bibliography on Sociocultural Theory and L2 Learning.
Also helpful is Resources for Researchers, consisting of lists of selected references (or bibliographies) on topics related to applied linguistics sponsored by the The International Research Foundation for English Language Education. Topics, not limited to English language teaching only, include Action Research, Anxiety in Language Learning and Assessment, Critical Pedagogy and Critical Research, Language Classroom Research, Pragmatics, Task Based Language Teaching, and many others. The lists are in Microsoft Word format.
Use with caution. Not all citations are 100% accurate. Some miss finer details like capitalization or punctuation. Proof the final citations according to a style manual.