I can't access that article myself, but here is its full abstract along with its DOI link to make the retrieval easier for anyone who has access to the Tetrahedron backfiles.
Tricyclic dimers of propenylphenyl ethers. I. NMR and stereochemistry
J. MacMillan, I. L. Martin, D. J. Morris, Tetrahedron 25(4), 905-914 (1969)
DOI:10.1016/0040-4020(69)85024-6 (http://dx.doi.org/10.1016/0040%2D4020%2869%2985024%2D6)
Abstract
From their NMR spectra, the ?- and ?-racemates of the phenylindanes, obtained by acid-induced dimerization of isohomogenol and isosafrole, are shown to possess the 1,2-cis-2,3-trans-and 1,2-trans-2,3-trans-configurations respectively. This conclusion contradicts the configurations previously assigned to these racemates. Metanethole the dimer of anethole is shown to be the ?-racemate, that is, the 1,2-trans-2,3-trans-racemate. The 1,2-cis-2,3-cis-configuration of the synthetic ?-racemates of metanethole and diisohomogenol is confirmed.