Chemical Process Principles, Parts 1, 2 and 3. Eds 19431947 O.A. Hougen, K.M. Watson Chemical Process Principles, Parts 1, 2 and 3. Eds 19431947 O.A. Hougen, K.M. Watson Chemical Process Principles, Parts 1, 2 and 3. Eds 19431947 O.A. Hougen, K.M. Watson Chemical Process Principles, Parts 1, 2 and 3. Eds 19431947 O.A. Hougen, K.M. Watson Chemical Process Principles, Parts 1, 2 and 3. Eds 19431947 O.A. Hougen, K.M. Watson Chemical Process Principles, Parts 1, 2 and 3. Eds 19431947 O.A. Hougen, K.M. Watson Chemical Process Principles, Parts 1, 2 and 3. Eds 19431947 O.A. Hougen, K.M. Watson