In what type of wave is the vibration perpendicular to the direction of travel of the of the wave

Certification programs are offered by all of the following except

An item not normally included in ansi recommendations, but recommended by other groups is: a) a syringe b) a blood pressure monitor c) a defibrillator d) all of the above

Ben is interested in using a source that provides original research, current and developing trends and experts within specific fields. which source should he use?