¥Hausmann (1982): -1, 0, +1
¥Vines (2000), Jolliffe, Uddin & Vines (2002): more integers –
gives so- called simple components
¥Chipman & Gu (2004): find ordinary EOFs, then truncate to –1, 0, +1
or –c1, 0, c2
¥Rousson & Gasser (2004): a technique that produces blocks of zeros
and blocks of equal non-zero loadings