It seems you're looking for a of a useful academic paper or resource related to Mushaf (the written Quranic text) and Al-Qira'at As-Sab' (the Seven Canonical Readings), specifically something numbered "39" (possibly a page, verse, or document reference like "39-ah" as a publication code).
Conclusion
mushaf qiraat sab‘ah
When you open a (especially a PDF scan), you will notice:
contemporary color-coded Mushaf
More commonly today, this term refers to a that marks the differences between the seven readings (often using red, green, blue dots) based on the canonical scholarly works that trace their sanad back to that early period.
A typical "Mushaf al-Qira'at al-Sab'ah" in PDF format includes: