TY - GEN AU - Parks, Edwin J AU - Herbert, R L C2 - , National Institute of Standards and Technology, Gaithersburg, MD DA - 1976-01-01 05:01:00 DO - https://doi.org/10.6028/NBS.IR.75-915 LA - en PB - , National Institute of Standards and Technology, Gaithersburg, MD PY - 1976 TI - A source of error in paper extract pH determinations ::contact between paper and reference electrodes ER -