Google to the rescue!
M39 is basic#5 x skunk #1
Basic #5 = NL#5
Nl# x skunk #1 = shiva skunk (sensi)
Incorrect, unless you forgot the #5. Its listed clear as day:
Sensi Seeds Feminized or Regular Cannabis Seeds
This is the best strain out of Skunk line. Shiva Skunk is the most reliable indoor and greenhouse variety with its exceptional vigour. An excellent plant for beginners or experts, Shiva Skunk stays tight and compact with large buds that have a high calyx-to-leaf ratio that makes for easy clipping. Its yields are better than the Skunk #1 what makes her perfect for cash croppers. Its very powerful and relaxing effect is surrounded with sweet pungency of the skunky smell.
Genetics : Skunk #1 x NL #5
Sex : Feminzied and Regular
Flowering Time : 45-55 Days
Type : Mostly Indica
Area : Indoor and Greenhouse