nestor and TD - Thanks for your informative comments.  They definitely pointed me in the right direction.  Sielecki does indeed cover 1.d4 Nf6 2.Nf3 e6 3.g3 b5 in his Keep It Simple 1.d4, but he refers to it as the "Extended Fianchetto".  His analysis of 1.d4 Nf6 2.Nf3 e6 3.g3 b5 4.Bg2 d5 is in a different chapter with the descriptive title "Black stops c2-c4".  

While Romanishin often played the sequence given by TD (1.Nf3 Nf6 2.c4 e6 3.g3 a6 4.Bg2 b5), a case could also be made to name 1.d4 Nf6 2.Nf3 e6 3.g3 b5 4.Bg2 d5 after him because he reached the position after the 4th move in his game with Raymond Keene in the 1973 IBM-B Amsterdam tournament.  (In this case, the position came via the transposition 1.Nf3 Nf6 2.g3 b5 3.Bg2 d5 4.d4 e6).  It seems plausible that Pavlovic chose to name the variation after Romanishin because of the game with Keene or due to the common feature of an early ...b5 as in the Romanishin System described by TD.

This approach with an early ...b5 seems pretty respectable since it's recommended in two Quality Chess opening books: Avurkh's Grandmaster Repertoire 11 - Beating 1.d4 Sidelines and Ntirlis' Playing 1.d4 d5: A Classical Repertoire, although neither author refers to Romanishin. 

It's certainly not the Nimzo after 1.d4 Nf6 2.Nf3 e6 3.g3. I was also thinking of 3...b5, which looks like 1.Nf3 Nf6 2.c4 e6 3.g3 a6 4.Bg2 b5, the Romanishin System (for Black!).

Kerangali wrote on 04/30/23 at 17:22:46:

When I saw announcement for this new book on the Everyman site the other day, I wondered if Pavlovic had attained Lakdawala-like levels of prolificacy because his two volumes on the Nimzo-Indian had just been released by Thinkers Publishing earlier this month. 

Based on the limited information in the pdf excerpt, it appears that the proposed repertoire resembles the one advocated by Sielecki in his Keep It Simple 1.d4 from 2019, with 1.d4 Nf6 2.Nf3 e6 3.g3.  Sielecki castled before playing c2-c4, which meant he avoided the Nimzo-Indian entirely.  I'm curious what move order Pavlovic uses to enter the Romanishin Variation of the Nimzo.

I found a new book for everyman about 1.d4 and strategic play and I am thinging to buy it.
I saw that it has  "The Romanishin Variation", it is against Grunfeld defence?
I do not see any "Grunfeld defence" chapter.
What is your opinion about this book from the pdf that is at the publisher site
The pdf https://cdn.shopify.com/s/files/1/0080/9284/4094/files/OR_Strategic_Play_with_1_...
The book https://everymanchess.com/products/opening-repertoire-strategic-play-with-1d4-1