Bramwell, Tom (June 16, 2001). "Half-Life: Blue Shift". Eurogamer. Gamer Network. Archived from the original on November 1, 2001. Retrieved April 15, 2024.
Bramwell, Tom (August 25, 2005). "Free Half-Life 1 Expansion". Eurogamer. Gamer Network. Archived from the original on October 19, 2023. Retrieved April 15, 2024.
Satterfield, Shane (November 8, 2000). "Sierra Explains Half-Life Delay". GameSpot. Fandom. Archived from the original on December 16, 2004. Retrieved April 15, 2024.
Walker, Trey (June 13, 2001). "Half-Life: Blue Shift ships". GameSpot. Fandom. Archived from the original on December 7, 2001. Retrieved April 15, 2024.
Satterfield, Shane (November 8, 2000). "Sierra Explains Half-Life Delay". GameSpot. Fandom. Archived from the original on December 16, 2004. Retrieved April 15, 2024.
Walker, Trey (June 13, 2001). "Half-Life: Blue Shift ships". GameSpot. Fandom. Archived from the original on December 7, 2001. Retrieved April 15, 2024.
Bramwell, Tom (June 16, 2001). "Half-Life: Blue Shift". Eurogamer. Gamer Network. Archived from the original on November 1, 2001. Retrieved April 15, 2024.
Bramwell, Tom (August 25, 2005). "Free Half-Life 1 Expansion". Eurogamer. Gamer Network. Archived from the original on October 19, 2023. Retrieved April 15, 2024.