See Theorem 1 and p.156, l.1 in Bobkov, Houdré & Tetali (2000). Note that λ2 there corresponds to 2(d − λ2) of the current article (see p.153, l.5) Bobkov, S.; Houdré, C.; Tetali, P. (2000), "λ∞, vertex isoperimetry and concentration", Combinatorica, 20 (2): 153–172, doi:10.1007/s004930070018, S2CID1173532.
See Theorem 1 and p.156, l.1 in Bobkov, Houdré & Tetali (2000). Note that λ2 there corresponds to 2(d − λ2) of the current article (see p.153, l.5) Bobkov, S.; Houdré, C.; Tetali, P. (2000), "λ∞, vertex isoperimetry and concentration", Combinatorica, 20 (2): 153–172, doi:10.1007/s004930070018, S2CID1173532.