TY  JOUR
TI  How to build a technical drawing surface with own and falling of shadows
KW  a technical drawing
KW  surface area
KW  axonometric projection
KW  secondary projection
KW  the ellipse
JO  Journal of Technical Research
AU  Nikiforov, V.M.
AU  Mal'ceva, E.A.
PY  2020
IS  6
PB  INFRA-M Academic Publishing LLC.