If you are searching for the version, you are likely looking for the revised editions that have modernized the vocabulary and layout.
Robert Krohn's "English Sentence Structure" is a well-regarded resource, but I couldn't find a direct link to an updated PDF. However, I can offer you some alternatives and insights to help you understand English sentence structure: englishsentencestructurerobertkrohnpdf updated
Why not just use Grammarly, Duolingo, or English Grammar in Use ? Here is the advantage of Krohn’s : If you are searching for the version, you
English Sentence Structure by Robert Krohn is a foundational, pattern-based ESL text designed for intensive practice, featuring a widely utilized 1971 revision that focuses on sentence construction. Highly regarded for classroom use, the resource maintains a strong reputation for developing natural fluency, according to reviews on ThriftBooks mielanguage.net English-Sentence-Structure-with-practice.pdf - mielanguage Here is the advantage of Krohn’s : English