#1 Young, Mark (Mark R.) author of The natural history of moths (97016968)
#3 Young, Mark, author of Homemade icecream naturally (LC undifferentiated 77008279)
#4 Young, Mark, editor of Guiness and World Almanac vols.; sometimes uses Mark C. Young.
#5 Young, Mark (Mark H.) writer, director and editor (LC 2010076693)
#6 Young, Mark, author of Off the grid.
#8 Young, Mark, 1972- author of The complete guide to swimming (LC 2011025860)
#9 Young, Mark - film producer, screenwriter (NOT Mark H. Young)
#10 Mark Young - director, producer and writer of "The Least Among You" (different than #5 and #9)