TY - RPRT TI - Complement Fixation with Simple Substances Containing Two or More Haptenic Groups. AU - D Pressman AU - D H Campbell AU - L Pauling PY - 1942 DO - 10.1073/pnas.28.3.77 UR - https://pubmed.ncbi.nlm.nih.gov/16578035/ ID - 16578035 ER -