| A | So Hard (The KLF Versus Pet Shop Boys) | 5:27 | ||
| B | It Must Be Obvious (UFO Mix) | 9:22 |
"It Must Be Obvious" recorded live at Trancentral.
℗&© 1990 Pet Shop Boys Partnership under exclusive license to EMI Records Ltd.
The label on B incorrectly credits Harold Faltermeyer as producer, while cover correctly only credits him for A.
| Title, Format | Label | Cat# | Country | Year | ||
|---|---|---|---|---|---|---|
| So Hard (7", Single) | Parlophone, Parlophone | r6269, 2040627 | UK | 1990 | ||
| So Hard (CD, Single) | Parlophone, Parlophone | CDR 6269, 2040622 | UK | 1990 | ||
| So Hard (12", Promo) | Parlophone | 12RDJ 6269 | UK | 1990 | ||
| So Hard (12") | Parlophone, EMI-Odeon, S.A. | 052 20 4062 6, 052 2040626 | Spain | 1990 | ||
| So Hard (Remix By David Morales) (CD, Maxi) | Parlophone, EMI | 560- 20 4177 2, CDP 560- 20 4177 2 | Germany | 1990 |