Font in maths books

I would like to know what is this beautiful font used to typeset maths books as
J.D. Moore’s Lectures on Seiber-Witten theory
and S. Morita’s Geometry of differential forms.

This font is much different than the one in this question.

I tried to use What The Font tool, but all fonts it suggested were much different. Identifont said that it was similar to Century Old Style. It looks like quite a good match, yet they look different.

Then I tried to use pdffonts. It gave me the following:

Times Bold                           TrueType          WinAnsi          yes no  no      23  0
Times Roman                          TrueType          WinAnsi          yes no  no      26  0
Times Italic                         TrueType          WinAnsi          yes no  no      37  0
Helvetica Bold Oblique               TrueType          WinAnsi          yes no  no      56  0
TCNFTU+HiddenHorzOCR                 CID Type 0C       Identity-H       yes yes yes     67  0
Helvetica                            TrueType          WinAnsi          yes no  no      88  0

This however does not look as Helvetica to me (I tried this) nor Times Roman from mathptmx package.

I wonder if you recognize this font. (Any idea what other tool I can use is very welcome 🙂