The Complete List of Suppliers for L-Threonine, N-[(9H-fluoren-9-ylmethoxy)carbonyl]-O-[O-2,3,4,6-tetra-O-acetyl-β-D-galactopyranosyl-(1→3)-O-[3,4,6-tri-O-acetyl-2-(acetylamino)-2-deoxy-β-D-glucopyranosyl-(1→6)]-4-O-acetyl-2-(acetylamino)-2-deoxy-α-D-galactopyranosyl]-, 1,1-dimethylethyl ester