The kit you have received was created by your colleagues. Please acknowledge the Principal Investigator, cite the article listed on the datasheet, and include the Addgene kit number in future publications.
Example for your Materials & Methods section:
Multiplex CRISPR/Cas9 Assembly System Kit was a gift from Takashi Yamamoto
(Addgene kit # 1000000055)
(Addgene kit # 1000000055)
Example for your References section:
Multiplex genome engineering in human cells using all-in-one CRISPR/Cas9 vector system. Sakuma T, Nishikawa A, Kume S, Chayama K, Yamamoto T. Sci Rep. 2014 Jun 23;4:5400. 10.1038/srep05400. PubMed 24954249.