PF= PF, pulp × Fweighted reference, pulp/(Fweighted reference, pulp + Freference, paper) + PF, paper × Freference, paper/(Fweighted reference, pulp + Freference, paper)
PF= PF, pulp × Fgewogen referentie, pulp/(Fgewogen referentie, pulp + Freferentie, papier) + PF, papier × Freferentie, papier/(Fgewogen referentie, pulp + Freferentie, papier).