APA (7th ed.) Citation
SCHWARTZ, I., & ET AL. (1999). THE PICTURE EXCHANGE COMMUNICATION SYSTEM ( PECS): COMMUNICATIVE OUTCOMES FOR YOUNG CHILDREN WITH DISABILITIES.
Chicago Style (17th ed.) Citation
SCHWARTZ, I.S, and ET AL. THE PICTURE EXCHANGE COMMUNICATION SYSTEM ( PECS): COMMUNICATIVE OUTCOMES FOR YOUNG CHILDREN WITH DISABILITIES. 1999.
MLA (9th ed.) Citation
SCHWARTZ, I.S, and ET AL. THE PICTURE EXCHANGE COMMUNICATION SYSTEM ( PECS): COMMUNICATIVE OUTCOMES FOR YOUNG CHILDREN WITH DISABILITIES. 1999.
Warning: These citations may not always be 100% accurate.