GTS-4E_Hardware_Integration_Manual_V1.0.0.pdf GTS-4E_Datasheet_V1.0.0.pdf GSD4e NMEA Reference Manual.pdf GTS-4E_RECOMMENDED PCB LAYOUT_V2.0.1_20101127.rar GSD4e One Socket Protocol Interface Control Document.pdf GT5012_V1.0.1_sch_20110315.pdf