It sounds like you're looking for a (likely the textbook or workbook), and you mentioned an interesting blog post — perhaps one that reviews, compares, or provides access to the PDF.
The Sogang 5A course package typically consists of a Student’s Book (Textbook) and a Workbook. The Student's Book is divided into distinct units, each focusing on a broad thematic area. Core Themes and Topics sogang 5a pdf
Because Sogang is a speaking-first textbook, do not treat the reading passages passively. It sounds like you're looking for a (likely
Warm-up questions and visual prompts to activate background knowledge. sogang 5a pdf