diff --git a/README.md b/README.md
index d0bc3a3..4a67748 100644
--- a/README.md
+++ b/README.md
@@ -13,7 +13,7 @@ The software supports single-layer and multi-layer shielding simulations, enabli
 🧠 Advanced features include:
 
 - Monte Carlo build-up factor corrections for improved accuracy
-- Gaussian Process extrapolation for enhanced prediction capabilities
+- Analytical fits (Shin-Ishii, Power x saturator, thin-plate-spline RBF) for build-up factor interpolation and extrapolation
 
 These tools allow engineers and researchers to perform fast and reliable radiation shielding assessments. 🚀
 
diff --git a/docs/api.md b/docs/api.md
index ecbb553..e14ce46 100644
--- a/docs/api.md
+++ b/docs/api.md
@@ -196,7 +196,7 @@ Analytical-form fit of build-up factor across a set of MC points. 1D inputs are
 
 **Methods:**
 
-- `interpolate(quantity=None, warn=True, **kwargs)` - returns an `InterpolationResult` at the given parameter values. If the fit has more than one available quantity (e.g. both `dose-AP` and `dose-AP-total`), `quantity=` is required to disambiguate; otherwise it defaults to the only one.
+- `interpolate(quantity=None, warn=True, **kwargs)` - returns an `InterpolationResult` at the given parameter values. If the fit has more than one available quantity (e.g. both `dose-AP-neutron` and `dose-AP-total`), `quantity=` is required to disambiguate; otherwise it defaults to the only one.
 
 ### `InterpolationResult`
 
diff --git a/docs/guide/studies/variable_material.md b/docs/guide/studies/variable_material.md
index 8991b62..6555a1c 100644
--- a/docs/guide/studies/variable_material.md
+++ b/docs/guide/studies/variable_material.md
@@ -20,7 +20,7 @@ VOID_THICKNESS = 1000
 CONCRETE_THICKNESS = 50
 source = rpk.Source(particle="neutron", energy=14.1e6)
 
-N_DOSE = f"dose-{GEOMETRY}"
+N_DOSE = f"dose-{GEOMETRY}-neutron"
 P_DOSE = f"dose-{GEOMETRY}-coupled-photon"
 TOTAL_DOSE = f"dose-{GEOMETRY}-total"  # auto-synthesized by compute_buildup
 
diff --git a/mkdocs.yml b/mkdocs.yml
index f2477ee..f686c8c 100644
--- a/mkdocs.yml
+++ b/mkdocs.yml
@@ -45,6 +45,9 @@ nav:
     - Uncollided flux in void: vnv/uncollided_flux_in_void.md
     - Transmission in void: vnv/transmission_in_void.md
     - Beer-Lambert single slab: vnv/beer_lambert_single_slab.md
+    - Neutron fit form quality: vnv/neutron_fit_quality.md
+    - Primary-photon fit form quality: vnv/primary_photon_fit_quality.md
+    - Secondary-photon fit form quality: vnv/secondary_photon_fit_quality.md
 
 plugins:
   - search