Personally, for me an integral part in technical development is economic calculations, that's for them I use this resource https://books.google.com.ua/books?id=GDBWBQAAQBAJ&pg=PA28&lpg=PA28&dq=technical+developments+are+economic+calculations&source = bl & ots = KMJ36kWrHU & sig = hdm8d45WiiNuFEZtfvMg0-9PFZE & hl = en & sa = X & ved = 0ahUKEwippsj1jJHXAhUHEpoKHWKfDDsQ6AEIJjAA # v = onepage & q = technical% 20developments% 20are% 20economic% 20calculations & f = false Also sometimes I use https://essayshark.com/personal-statement-writing.html If my advice is helpful, then I will be glad to listen to any criticism, suggestions. If you have any more materials, ideas, then you can share with me. Thank you!