What do you use for SStotal when calculating effect size η2 on SPSS for mixed-design ANOVA?

If you want to derive η2 values from a 2-or-more way ANOVA with at least one within-subjects factor, what items on the SPSS output do you add up to arrive at the total sum of squares (SStotal) for the following equation?

η2 = SSeffect/SStotal

With outputs for 2-or-more ANOVA with only between-subjects factors, you just use the values from ‘corrected total,’ but when there is a within-subjects factor, you see two sections, one for between-factor(s) and the other within-factor(s), and there is no ‘corrected total’ or anything which you can use for the SStotals.
I’m presuming you add some things to get the SStotal, and you throw each SSeffect from the output into the numerator, and the SStotal into the denominator of the equation.

What would you add up?